Gearbox odyssey
Discussion
Having managed to get a grand total of 50 miles out of my one-owner 1998 Chimaera 450, I find I have completely lost 5th gear. I expected this, although perhaps not quite so soon, because the car was difficult to get in 5th when I test drove it. Took a gamble anyway. Oh well...
The symptoms, as far as I can tell from my limited experience, are those of a failed linkage rather than a gearbox internal thing. 5th was quite happy to go in when you found it, but that got less and less frequent. In the end, you just feel like you're pushing hard against the end stop.
Luckily, I have a friendly mechanic in the village who's a) worked on TVR's before and b) doesn't mind me helping out. So I've decided to have it fixed "at home" rather than by a TVR specialist. David Batty was my original plan, but he's 150 miles away and I can't get there in 4th.
So for posterity, and in case I don't return to tell the tale, here's a diary of my gearbox experience.
Day #1 - going in through the top.
----------------------------------
The plan is to look at the gearbox external linkage to see if anything's loose. That'd be a quick fix, so fingers crossed.
Lift out base of the change pocket, revealing the fibre glass skin of the transmission tunnel cover in which are two screws. Remove these. After some experimental tugging, find that there are two further screws, one on each side of the tunnel, down at the front where your knee rests. Not mentioned in book.
The door opener is held on by a tiny and highly inaccessible grub screw, freed using a weeny (2mm?) Allen key in about 10 quarter-turns. Damn fiddly. The door opener cables are hooked round the end of the tunnel cover but are easily parted. Handbrake needs to be slackened by the adjuster underneath the car. Gear knob unscrews, then the tunnel removes easily (but is still connected to the car by the cables to the electric window buttons).
The bible now describes a riveted inspection plate allowing access to the top of the gearbox. Riveted? I wish. Mine is screwed down in about 8 places, with all screws glued down either under the carpet or a block of foam underlay. The carpet and foam have to be gently pulled apart, but you can't get squeamish 'cos there's much worse to come.
Once the screws are out, the inspection panel won't budge. It's held down all round by a very liberal helping of some extremely sticky black trim sealant. Prise it off, hoping that the panel won't crack in half. At this point it begins to feel like I am pulling the entrails out of the car.
Once the gear lever (unscrewed) and handbrake handle (twisted off) have come out, the inspection panel is finally free, revealing the gearbox linkage.
The remote linkage rod extends forward from the gear lever into some kind of sleeve joint that I can't see - probably just a guide. The gear lever is connected to the middle of the rod by a hinge, and underneath by a rather dry and rusty looking ball joint. At the rear of the rod, another descender connects to the gear selector itself. Disconnect the gearbox from the remote linkage by undoing the rear hinge bolt and tapping out the small plastic sleeve that it sits in.
Clamping some mole grips on the gearbox gear selector stub as a temporary gear stick, find that 5th gear still can't be selected. Bum. This means that we'll have to drop the gearbox, because the access panel can't be removed from above due to a diagonal chassis brace which is in the way.
We'll leave the gearbox for day #2, but do some prep. work before we close up for today. This is very close to the way described in the bible, with one or two minor differences: firstly, we drop the exhaust (having first unbolted the anti-roll bar and let it dangle) but find we can't slide it out backwards without breaking a window. So it stays under the car. Next, we find that, once the bolts on the drive plate have been disconnected, removal of the prop shaft is much easier than the book suggests.
Also unbolt and remove the transverse chassis brace just in front of the gearbox rear mounting, then remove and push aside the clutch slave cylinder. This looks like it will have to be jiggled when the gearbox does come out, because the copper pipe is caught round a bend in the gearbox body.
That's it for the first afternoon's work. Tomorrow afternoon we'll drop the box, fix the easily located linkage problem, lube up the propshaft, etc.
I'm also highly tempted to replace the clutch. The car has 30k miles on it, and I've heard they go any time from 30-50k. The clutch has gone within 10k miles on every other blasted car I've bought, so why not beat fate this time while I have the chance?
Day #2 – red legs
-----------------
With most of the surrounding area cleared already, should be simple to get the gearbox out, right? Standing underneath the car, with the gearbox supported by a long jack, unbolt the gearbox rear rubber mounts both at top and bottom and slide them out. Using a very long (1m) assembly of extension bars and standing with head where the prop shaft was, a friend holding the socket on at the other end, undo the bolts on the clutch bell. Gently push that slave cylinder right out of the way and disconnect the reversing light switch.
The gearbox is now completely unbolted. But it won't come out of the car, due to TVR's little joke on the amateur mechanic. Remember that remote linkage rod in some kind of sleeve joint at the front? Well, the inside of the sleeve is a pin bolted to the top of the gearbox. It can't be seen from anywhere, either in the passenger compartment, or from the engine bay, or from underneath. And the really funny part of the joke is that the pin passes over a chassis tube, which means that the gearbox is now hooked on the chassis, stopping you from pulling it back more than about 1 inch. You have to unbolt it blind, using 2 spanners, with your arms above your head and your hands stuffed in the small crevices either side of the clutch bell. Expect to lose some skin.
With the pin out of the way, the box finally comes free. Now is the time you wish you'd done what the book said and covered the open end, because it chooses this moment to pee gearbox oil all over your trousers. Thank god I changed into old shoes...
The box now has to be jiggled to get it out of the car, because the various lumps on it interfere with the chassis. Backwards until the drive shaft comes out from the clutch, then down and forwards, then twisted once, tilted down at the back and twisted again.
Now undo the plate holding the selector in place and remove it, holding your breath and confidently expecting to see a broken ball joint. Nope. It turns out I don't have type-A 5th gear problem, I have type-B. The type-B is where the 5th gear syncromesh cracks in two and jams inside the gearbox.
Bugger.
This means a) total gearbox rebuild and b) my gutted Chim sitting in the village garage for up to 2 weeks. I could push it home, it's not far. But I'd probably die of shame, having proudly arrived in it only 3 days ago.
One consolation is that the clutch would have probably gone soon and the box would have had to come off anyway. It's not too worn, but the springs have given up and a couple of them are really loose. This also clears up a minor worry that I hadn't admitted to anyone yet – the car was quite jerky at low revs and low speed, accompanied by a clanking from underneath. Kind of like massive play in the drive train. That was all down to the clutch. The rest of the drive train is perfect.
OK. Day 3 will be a classroom exercise, called “find a new gearbox before the friendly mechanic kicks the Chim out onto the street.” If anyone is reading this, and has got this far, and knows where I can get an exchange unit for less than about £600, please let me know.
Updates to follow...
The symptoms, as far as I can tell from my limited experience, are those of a failed linkage rather than a gearbox internal thing. 5th was quite happy to go in when you found it, but that got less and less frequent. In the end, you just feel like you're pushing hard against the end stop.
Luckily, I have a friendly mechanic in the village who's a) worked on TVR's before and b) doesn't mind me helping out. So I've decided to have it fixed "at home" rather than by a TVR specialist. David Batty was my original plan, but he's 150 miles away and I can't get there in 4th.
So for posterity, and in case I don't return to tell the tale, here's a diary of my gearbox experience.
Day #1 - going in through the top.
----------------------------------
The plan is to look at the gearbox external linkage to see if anything's loose. That'd be a quick fix, so fingers crossed.
Lift out base of the change pocket, revealing the fibre glass skin of the transmission tunnel cover in which are two screws. Remove these. After some experimental tugging, find that there are two further screws, one on each side of the tunnel, down at the front where your knee rests. Not mentioned in book.
The door opener is held on by a tiny and highly inaccessible grub screw, freed using a weeny (2mm?) Allen key in about 10 quarter-turns. Damn fiddly. The door opener cables are hooked round the end of the tunnel cover but are easily parted. Handbrake needs to be slackened by the adjuster underneath the car. Gear knob unscrews, then the tunnel removes easily (but is still connected to the car by the cables to the electric window buttons).
The bible now describes a riveted inspection plate allowing access to the top of the gearbox. Riveted? I wish. Mine is screwed down in about 8 places, with all screws glued down either under the carpet or a block of foam underlay. The carpet and foam have to be gently pulled apart, but you can't get squeamish 'cos there's much worse to come.
Once the screws are out, the inspection panel won't budge. It's held down all round by a very liberal helping of some extremely sticky black trim sealant. Prise it off, hoping that the panel won't crack in half. At this point it begins to feel like I am pulling the entrails out of the car.
Once the gear lever (unscrewed) and handbrake handle (twisted off) have come out, the inspection panel is finally free, revealing the gearbox linkage.
The remote linkage rod extends forward from the gear lever into some kind of sleeve joint that I can't see - probably just a guide. The gear lever is connected to the middle of the rod by a hinge, and underneath by a rather dry and rusty looking ball joint. At the rear of the rod, another descender connects to the gear selector itself. Disconnect the gearbox from the remote linkage by undoing the rear hinge bolt and tapping out the small plastic sleeve that it sits in.
Clamping some mole grips on the gearbox gear selector stub as a temporary gear stick, find that 5th gear still can't be selected. Bum. This means that we'll have to drop the gearbox, because the access panel can't be removed from above due to a diagonal chassis brace which is in the way.
We'll leave the gearbox for day #2, but do some prep. work before we close up for today. This is very close to the way described in the bible, with one or two minor differences: firstly, we drop the exhaust (having first unbolted the anti-roll bar and let it dangle) but find we can't slide it out backwards without breaking a window. So it stays under the car. Next, we find that, once the bolts on the drive plate have been disconnected, removal of the prop shaft is much easier than the book suggests.
Also unbolt and remove the transverse chassis brace just in front of the gearbox rear mounting, then remove and push aside the clutch slave cylinder. This looks like it will have to be jiggled when the gearbox does come out, because the copper pipe is caught round a bend in the gearbox body.
That's it for the first afternoon's work. Tomorrow afternoon we'll drop the box, fix the easily located linkage problem, lube up the propshaft, etc.
I'm also highly tempted to replace the clutch. The car has 30k miles on it, and I've heard they go any time from 30-50k. The clutch has gone within 10k miles on every other blasted car I've bought, so why not beat fate this time while I have the chance?
Day #2 – red legs
-----------------
With most of the surrounding area cleared already, should be simple to get the gearbox out, right? Standing underneath the car, with the gearbox supported by a long jack, unbolt the gearbox rear rubber mounts both at top and bottom and slide them out. Using a very long (1m) assembly of extension bars and standing with head where the prop shaft was, a friend holding the socket on at the other end, undo the bolts on the clutch bell. Gently push that slave cylinder right out of the way and disconnect the reversing light switch.
The gearbox is now completely unbolted. But it won't come out of the car, due to TVR's little joke on the amateur mechanic. Remember that remote linkage rod in some kind of sleeve joint at the front? Well, the inside of the sleeve is a pin bolted to the top of the gearbox. It can't be seen from anywhere, either in the passenger compartment, or from the engine bay, or from underneath. And the really funny part of the joke is that the pin passes over a chassis tube, which means that the gearbox is now hooked on the chassis, stopping you from pulling it back more than about 1 inch. You have to unbolt it blind, using 2 spanners, with your arms above your head and your hands stuffed in the small crevices either side of the clutch bell. Expect to lose some skin.
With the pin out of the way, the box finally comes free. Now is the time you wish you'd done what the book said and covered the open end, because it chooses this moment to pee gearbox oil all over your trousers. Thank god I changed into old shoes...
The box now has to be jiggled to get it out of the car, because the various lumps on it interfere with the chassis. Backwards until the drive shaft comes out from the clutch, then down and forwards, then twisted once, tilted down at the back and twisted again.
Now undo the plate holding the selector in place and remove it, holding your breath and confidently expecting to see a broken ball joint. Nope. It turns out I don't have type-A 5th gear problem, I have type-B. The type-B is where the 5th gear syncromesh cracks in two and jams inside the gearbox.
Bugger.
This means a) total gearbox rebuild and b) my gutted Chim sitting in the village garage for up to 2 weeks. I could push it home, it's not far. But I'd probably die of shame, having proudly arrived in it only 3 days ago.
One consolation is that the clutch would have probably gone soon and the box would have had to come off anyway. It's not too worn, but the springs have given up and a couple of them are really loose. This also clears up a minor worry that I hadn't admitted to anyone yet – the car was quite jerky at low revs and low speed, accompanied by a clanking from underneath. Kind of like massive play in the drive train. That was all down to the clutch. The rest of the drive train is perfect.
OK. Day 3 will be a classroom exercise, called “find a new gearbox before the friendly mechanic kicks the Chim out onto the street.” If anyone is reading this, and has got this far, and knows where I can get an exchange unit for less than about £600, please let me know.
Updates to follow...
Welcome to the joys of TVR ownership. Don't get disheartened you'll soon have that grin back on your face when you finally get it all back together again and you're blasting down the road (with the top off of course).
I await the next installment with baited breath (whatever that means).
Nick
I await the next installment with baited breath (whatever that means).
Nick
Sorry to hear about your chim, you could try www.gearboxman.co.uk for an exchange unit.
Keep us all upto date on what happens!!
Keep us all upto date on what happens!!
Excellent description of practical TVR gearbox removal! Having just done the same and rebuilt the box on my Griff I could sense your frustrations at the various obstacles!!
A word of advice... Put the bellhousing onto the engine BEFORE to refit the gearbox and you will find it much easier to manipulate AND you can sort out that remote linkage much more easily.
Gearboxman was where I was going to get a box from but then decided to rebuild it myself having bought a complete rebuild kit with a manual.
Best of luck
Neil
A word of advice... Put the bellhousing onto the engine BEFORE to refit the gearbox and you will find it much easier to manipulate AND you can sort out that remote linkage much more easily.
Gearboxman was where I was going to get a box from but then decided to rebuild it myself having bought a complete rebuild kit with a manual.
Best of luck
Neil
Day #3 - shell out
------------------
I spoke to David Batty today and he's sending me a recon gearbox plus a complete clutch kit by TNT, delivery by 12pm tomorrow. How's about that for quick service ? The clutch kit is £350+VAT, gearbox TBD but probably around £600. Starting to make the £250 I bargained off the car look a teensy bit stretched.
David also gave me the same advice about the clutch bell. We're wondering why we didn't think of that and save ourselves a fair bit of bother. Duh. Never mind, at least putting it back on will be easier.
David also very kindly phoned back and left a voice mail to the effect that a) that these gearboxes need Dexron TQD3 (auto transmission fluid) and b) shouldn't be overfilled. I do like people who genuinely care about the things they are selling.
Mind you, I probably would have noticed if I'd got the wrong kind of oil because the old gearbox contents are all over my shoes and trousers. Plus I own a Range Rover, so I've seen my fair share of auto fluid, albeit usually as dense white smoke...
So, fingers crossed, I might be up and running again by tomorrow evening.
------------------
I spoke to David Batty today and he's sending me a recon gearbox plus a complete clutch kit by TNT, delivery by 12pm tomorrow. How's about that for quick service ? The clutch kit is £350+VAT, gearbox TBD but probably around £600. Starting to make the £250 I bargained off the car look a teensy bit stretched.
David also gave me the same advice about the clutch bell. We're wondering why we didn't think of that and save ourselves a fair bit of bother. Duh. Never mind, at least putting it back on will be easier.
David also very kindly phoned back and left a voice mail to the effect that a) that these gearboxes need Dexron TQD3 (auto transmission fluid) and b) shouldn't be overfilled. I do like people who genuinely care about the things they are selling.
Mind you, I probably would have noticed if I'd got the wrong kind of oil because the old gearbox contents are all over my shoes and trousers. Plus I own a Range Rover, so I've seen my fair share of auto fluid, albeit usually as dense white smoke...
So, fingers crossed, I might be up and running again by tomorrow evening.
Day #4 – all coming together
The gearbox and new clutch assembly arrived from David Batty today. Carriage was £105+VAT! And TNT managed to drop it on the reversing light switch, which was brand new, knackering it. But for good measure, they dropped it on the other side too. This was presumably done so that gearbox oil could leak through onto the new clutch.
Needless to say, I have sworn vengeance, which I shall visit on them unto the fourth generation, so that they are scattered as the dust.
But for now, I have to take the hit and move on.
First some of the old bits have to be moved over onto the new box. The big ball joint, the rose joint (where that pin at the front of the remote linkage arm connects), the bridge piece that holds the gear lever pivot, and the mounting plate for the gearbox rear mount. Oh yeah, and fit a new reversing light switch. Grrr.
Dob some grease in the gear selector and some hylomar round the ball joint top plate before bolting on. Nice to be doing up bolts rather than undoing them – definitely on the homeward leg.
Next the clutch. Clean off the gearbox oil, courtesy of TNT (grr, etc). Bung in the clutch alignment tool, which centres the thing in the mechanism. I’ve never used one of these things before – it’s interesting to see how they work. Put the clutch assembly over the flywheel and do up the bolts a half-turn at a time, working on opposite pairs to avoid bending the case.
Next take the clutch release arm out of the bell and replace the clutch release bearing. It is on pretty hard, so a hydraulic press is needed to get the old one off. The new one just taps on.
Put the release bearing back in the arm, and the arm in the bell, which was pretty corroded and had to be cleaned up. This was bimetallic corrosion (otherwise known as Range Rover disease), so to prevent it happening again, spray the gearbox front with aluminium grease.
Now the bell can be put back in, taking care that the release bearing doesn’t fall off the arm. The two longer bolts go on the right hand side, on the starter motor bulge. One of them takes the clip for the slave cylinder hydraulic pipe, so we leave that one for now. Make sure the engine is well supported now, as we are going to be bolting heavy stuff on.
Remember just in time to bolt the linkage pin back into the rose joint. Much easier with the box off. Remember to route it over the chassis tube. Slide the remote linkage rod back over the pin, in case it’s hard to do with the gearbox in place.
Now the box itself. Not looking forward to this because I’ve done this before and I know how hard it is to get them on. Due to the tight tolerances, the gearbox shaft won’t go in the clutch unless they are aligned absolutely perfectly. Bit of copper grease on the shaft, then offer it up, each of us holding one end. I have one hand on the shaft and one in the clutch bell lining up the release bearing. Pop! Goes in first time, leaving us gobsmacked. Last time I did a gearbox that bit took 2 hours and I went hoarse from swearing. Perhaps this was easier because we didn’t have the bell on.
The box has to be drawn together with the bell by tightening the bolts. In turns, and carefully feeling the force applied through the socket in case it’s not going on straight. Once this is done, repace the metal guard plate at the lower front of the bell (the one I forgot to mention we took off on day 2).
Now refit the slave cylinder. This is a pig of a job. The pipe is stiff, and the bolts don’t want to go in unless the cylinder is lined up just right. Takes two people to do this really. Make sure that the plunger goes into the cylinder as you offer it up.
Slip the rubber rear mounting blocks back into their slots and tighten up. Put that long bolt in the clutch bell with its clip. Need a long socket extension again for that one.
Sit in the car and try out the clutch action. Momentarily puzzle about how to open the door, as a) the battery is disconnected and b) the interior door opener is in pieces. Luckily you can lean in and twist the opener even though it’s not attached to the car.
Well, that’s enough for today. Tomorrow, just a bit to do underneath: chassis brace, exhaust, anti-roll bar. Oh and the prop shaft, so the engine will have something to turn. Then back to the passenger compartment and try to push all those guts back in.
The gearbox and new clutch assembly arrived from David Batty today. Carriage was £105+VAT! And TNT managed to drop it on the reversing light switch, which was brand new, knackering it. But for good measure, they dropped it on the other side too. This was presumably done so that gearbox oil could leak through onto the new clutch.
Needless to say, I have sworn vengeance, which I shall visit on them unto the fourth generation, so that they are scattered as the dust.
But for now, I have to take the hit and move on.
First some of the old bits have to be moved over onto the new box. The big ball joint, the rose joint (where that pin at the front of the remote linkage arm connects), the bridge piece that holds the gear lever pivot, and the mounting plate for the gearbox rear mount. Oh yeah, and fit a new reversing light switch. Grrr.
Dob some grease in the gear selector and some hylomar round the ball joint top plate before bolting on. Nice to be doing up bolts rather than undoing them – definitely on the homeward leg.
Next the clutch. Clean off the gearbox oil, courtesy of TNT (grr, etc). Bung in the clutch alignment tool, which centres the thing in the mechanism. I’ve never used one of these things before – it’s interesting to see how they work. Put the clutch assembly over the flywheel and do up the bolts a half-turn at a time, working on opposite pairs to avoid bending the case.
Next take the clutch release arm out of the bell and replace the clutch release bearing. It is on pretty hard, so a hydraulic press is needed to get the old one off. The new one just taps on.
Put the release bearing back in the arm, and the arm in the bell, which was pretty corroded and had to be cleaned up. This was bimetallic corrosion (otherwise known as Range Rover disease), so to prevent it happening again, spray the gearbox front with aluminium grease.
Now the bell can be put back in, taking care that the release bearing doesn’t fall off the arm. The two longer bolts go on the right hand side, on the starter motor bulge. One of them takes the clip for the slave cylinder hydraulic pipe, so we leave that one for now. Make sure the engine is well supported now, as we are going to be bolting heavy stuff on.
Remember just in time to bolt the linkage pin back into the rose joint. Much easier with the box off. Remember to route it over the chassis tube. Slide the remote linkage rod back over the pin, in case it’s hard to do with the gearbox in place.
Now the box itself. Not looking forward to this because I’ve done this before and I know how hard it is to get them on. Due to the tight tolerances, the gearbox shaft won’t go in the clutch unless they are aligned absolutely perfectly. Bit of copper grease on the shaft, then offer it up, each of us holding one end. I have one hand on the shaft and one in the clutch bell lining up the release bearing. Pop! Goes in first time, leaving us gobsmacked. Last time I did a gearbox that bit took 2 hours and I went hoarse from swearing. Perhaps this was easier because we didn’t have the bell on.
The box has to be drawn together with the bell by tightening the bolts. In turns, and carefully feeling the force applied through the socket in case it’s not going on straight. Once this is done, repace the metal guard plate at the lower front of the bell (the one I forgot to mention we took off on day 2).
Now refit the slave cylinder. This is a pig of a job. The pipe is stiff, and the bolts don’t want to go in unless the cylinder is lined up just right. Takes two people to do this really. Make sure that the plunger goes into the cylinder as you offer it up.
Slip the rubber rear mounting blocks back into their slots and tighten up. Put that long bolt in the clutch bell with its clip. Need a long socket extension again for that one.
Sit in the car and try out the clutch action. Momentarily puzzle about how to open the door, as a) the battery is disconnected and b) the interior door opener is in pieces. Luckily you can lean in and twist the opener even though it’s not attached to the car.
Well, that’s enough for today. Tomorrow, just a bit to do underneath: chassis brace, exhaust, anti-roll bar. Oh and the prop shaft, so the engine will have something to turn. Then back to the passenger compartment and try to push all those guts back in.
Day #5
If anyone's still reading this, I now have my Chim back on the road! Just refitted the things I mentioned, filled the gearbox with Dextron III (noted it seemed to take 2.5 litres, not 2.5 pints as the book said, and I'm sure I didn't overfill it.)
Slight dramatic moment as I dropped the plastic sleeve for the gear linkage into the open transmission tunnel. Never did find it, will have to open it up again when I get a new one. Another as the immobiliser came up in a funny mode and the hazard lights flashed whenever the door was open. Cleared this by pressing the remote a few times.
Gear change action is now the way I want it. Car seems happier too. All in all... result!
If anyone's still reading this, I now have my Chim back on the road! Just refitted the things I mentioned, filled the gearbox with Dextron III (noted it seemed to take 2.5 litres, not 2.5 pints as the book said, and I'm sure I didn't overfill it.)
Slight dramatic moment as I dropped the plastic sleeve for the gear linkage into the open transmission tunnel. Never did find it, will have to open it up again when I get a new one. Another as the immobiliser came up in a funny mode and the hazard lights flashed whenever the door was open. Cleared this by pressing the remote a few times.
Gear change action is now the way I want it. Car seems happier too. All in all... result!
Well done Steve!
2.5 litres is about right. I expect your first few miles will have you thinking over the assembly process wondering if there is anything you forgot to tighten up......
Good job though and hopefully your account of the work may inspire others to have a go should the need arise!
Neil
2.5 litres is about right. I expect your first few miles will have you thinking over the assembly process wondering if there is anything you forgot to tighten up......
Good job though and hopefully your account of the work may inspire others to have a go should the need arise!
Neil
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