Strange gearbox/clutch problem (V8/LT77)
Discussion
Well I've been having a strange problem over the past week or so, symptoms are:
- Gets stuck in 1st especially when giving it beans
- Sometimes gets stuck in 3rd too.
- Crashing (lack of syncro) into 2nd or 3rd, fairly often, occasionally 4th or 5th.
- Usually bad when moving (i.e. rear wheels input to back of box) and OK when stationary.
- Sometimes works perfectly.
- Pumping the clutch 10 times sometimes makes it better.
- It isn't losing fluid, and the clutch pedal feels solid enough. The bite point feels normal and it will allow the engine to rev as you press past the bite point.
- Reverse works perfectly no crunching
- No problems with the remote linkage bushes - it's completely solid.
So I tried bleeding the clutch today, and took it for a spin, it was a bit better but some of the symptoms reappeared.
Just now I let some gearbox oil out and cleaned the magnetic plug - not a huge amount of filings on there (I've seen much worse). The let-out oil is a bit silvery. I topped up but it took a litre - much more than I let out. I shall report back if it's any better but this will be tomorrow now as I have started on the wine.
So - any ideas? Do I have to buy an endoscope to check out the release fork/pivot?
It's an 'E' suffix box by the way - and I just noticed that the oil drain plug is a much bigger diameter than the usual LT77 size...
I have taken to double-declutching to continue driving but I don't like the time delay changing gear - lucky I have bags of torque so can go into less-gear-changes mode!!
- Gets stuck in 1st especially when giving it beans
- Sometimes gets stuck in 3rd too.
- Crashing (lack of syncro) into 2nd or 3rd, fairly often, occasionally 4th or 5th.
- Usually bad when moving (i.e. rear wheels input to back of box) and OK when stationary.
- Sometimes works perfectly.
- Pumping the clutch 10 times sometimes makes it better.
- It isn't losing fluid, and the clutch pedal feels solid enough. The bite point feels normal and it will allow the engine to rev as you press past the bite point.
- Reverse works perfectly no crunching
- No problems with the remote linkage bushes - it's completely solid.
So I tried bleeding the clutch today, and took it for a spin, it was a bit better but some of the symptoms reappeared.
Just now I let some gearbox oil out and cleaned the magnetic plug - not a huge amount of filings on there (I've seen much worse). The let-out oil is a bit silvery. I topped up but it took a litre - much more than I let out. I shall report back if it's any better but this will be tomorrow now as I have started on the wine.
So - any ideas? Do I have to buy an endoscope to check out the release fork/pivot?
It's an 'E' suffix box by the way - and I just noticed that the oil drain plug is a much bigger diameter than the usual LT77 size...
I have taken to double-declutching to continue driving but I don't like the time delay changing gear - lucky I have bags of torque so can go into less-gear-changes mode!!
Yeah I was wondering about this but what could go wrong with a piston in a bore? If it's moving and not leaking it must be displacing the fluid (I have bled out any air). Same applies to the other end - the fluid is incompressible so must move the piston. It's all a bit wierd.
I have one of each as a replacement so if the g/b fluid top up doesn't work that's the next easiest thing to change. Then after that it's the release arm, but I shall take a look while the slave is out.
I have one of each as a replacement so if the g/b fluid top up doesn't work that's the next easiest thing to change. Then after that it's the release arm, but I shall take a look while the slave is out.
All in good time - if it's just the master then I won't do.
In the mean time progress with the replacement has been slow.
Firstly the clevis pin is siezed on the clutch lever. So I undid the rod from the lever bracket.
Then the new rod has a different thread - so I swapped over the rods.
Lastly the new clutch has a smaller thread on the pipe union than the old one. So what do I do - either get a new mating end and re-flare the pipe? Or shall I drill out the hole and tap it for the original connector - in which case what thread is it - 3/8" UNF possibly? Not sure which is the best option.... either way it's a load of hassle getting the pipe end sorted.... or buying some taps.
In the mean time progress with the replacement has been slow.
Firstly the clevis pin is siezed on the clutch lever. So I undid the rod from the lever bracket.
Then the new rod has a different thread - so I swapped over the rods.
Lastly the new clutch has a smaller thread on the pipe union than the old one. So what do I do - either get a new mating end and re-flare the pipe? Or shall I drill out the hole and tap it for the original connector - in which case what thread is it - 3/8" UNF possibly? Not sure which is the best option.... either way it's a load of hassle getting the pipe end sorted.... or buying some taps.
Ha ha - well when I get the hydraulics sorted I will shag it some more!!!
In the mean time I got a smaller brake union nut from a local garage and stuck it on the pipe and flared it (made a flaring tool for the purpose).
I have the new master on but it isn't taking fluid from the reservoir into the system, so I am hoping to borrow a pressure bleeding kit tomorrow to force the fluid in.
Anyone experienced this problem before - it is a bit odd?
In the mean time I got a smaller brake union nut from a local garage and stuck it on the pipe and flared it (made a flaring tool for the purpose).
I have the new master on but it isn't taking fluid from the reservoir into the system, so I am hoping to borrow a pressure bleeding kit tomorrow to force the fluid in.
Anyone experienced this problem before - it is a bit odd?
Well I put a pressure system on top of the reservoir (DIY - an old cap, a rugby ball inflation needle and an electric compressor) but even that struggled to force any fluid in. So I now think there is a defect with the new master cylinder.
The old cylinder looks great inside - no signs of wear or scoring - so I may just try and get a seal kit for it as I have to take off the new master anyways. Hmmmm.
The old cylinder looks great inside - no signs of wear or scoring - so I may just try and get a seal kit for it as I have to take off the new master anyways. Hmmmm.
I have filtered my previous change of SMX-S for re-use, although I was slightly worried that the micron-sized particles wouldn't be filtered out.
I suppose doing this and changing on a regular basis is much better than leaving it in which is what most people do (and top up occasionally).
Is the moly in black axle grease the same stuff as what you get in Molyslip etc?
I suppose doing this and changing on a regular basis is much better than leaving it in which is what most people do (and top up occasionally).
Is the moly in black axle grease the same stuff as what you get in Molyslip etc?
Well in the mean time I have put the clutch back together. The new master is off - it seems to have a reservoir/pistorn end seal that only breaks open when the cluch is let open extremely quickly. If you let off at a normal rate it won't open to the reservoir. The end rubber seems much deeper than usual and consequently is sealing off the reservoir almost all the time.
So I shimmed out the end washer on the original master with a couple of small washers and put it back together, it bled straight away and is operating smoothly again.
Now for the gearbox - well on a short drive there were a few notchy moments but it seemed generally OK. Hopefully the oil top-up has helped a bit, but time will tell on a longer drive. If all else fails it's the white spirit treatment and a few litres of Mobil 1 or Castrol.
So I shimmed out the end washer on the original master with a couple of small washers and put it back together, it bled straight away and is operating smoothly again.
Now for the gearbox - well on a short drive there were a few notchy moments but it seemed generally OK. Hopefully the oil top-up has helped a bit, but time will tell on a longer drive. If all else fails it's the white spirit treatment and a few litres of Mobil 1 or Castrol.
OK on a 20-mile drive the same problems resurfaced so it looks like the flushing treatment.
For a refill Castrol seem to do this stuff now in 0W/40:
Edge Sport 0w/40 1 litre For high performance and modified modern 14.99
Edge Sport 0w/40 4 litre vehicles fully synthetic sports performance 46.15
Is this the same stuff as RS (or has supercedded it?)
Mobil 1 0W40 seems easy enough to come by.
For a refill Castrol seem to do this stuff now in 0W/40:
Edge Sport 0w/40 1 litre For high performance and modified modern 14.99
Edge Sport 0w/40 4 litre vehicles fully synthetic sports performance 46.15
Is this the same stuff as RS (or has supercedded it?)
Mobil 1 0W40 seems easy enough to come by.
My lube change is imminent - 40 quids worth of Mobil 1 purchased (less halfrauds staff discount - mates rates) should be enought for 2 changes over the years.
Strangely Halfrauds didn't have the green molyslip in (despite showing it in stock online) but I may have half a tube in the barn.
White spirit and ATF for flushing - I have a plenty.
Strangely Halfrauds didn't have the green molyslip in (despite showing it in stock online) but I may have half a tube in the barn.
White spirit and ATF for flushing - I have a plenty.
Hmmm I ordered the Green Molyslip syringe like wot HJ2 posted (and I have used before) but a Purple tube of Holts molyslip tuned up this morning which is really annoying because I could have had this 3 days ago for 3 quid less from Halfrauds.
So - has anyone used the Purple tube - it is equivalent to the green syringe?
Also Martin your adapter turned up too (thanks!) so I have no excuse not to fiddle with the car again this weekend!
So - has anyone used the Purple tube - it is equivalent to the green syringe?
Also Martin your adapter turned up too (thanks!) so I have no excuse not to fiddle with the car again this weekend!
Well I think I'm getting there at last. The new master is back on but was a b'stard to bleed. I ended up bleeding the master on its own then back-bleeding from the slave to flush the air back up the pipe. It seemed to work but the action was too low so I have just adjusted the pushrod from the pedal to the master to bring the bite point a bit higher, I'll report more tomorrow after another drive.
P.S. I whinged on ebay to Wilco direct for their change in supply and got a fiver refund - result!!!
P.S. I whinged on ebay to Wilco direct for their change in supply and got a fiver refund - result!!!
Edited by adam quantrill on Monday 5th March 21:18
So - the plot thickens. I now have excellent clutch action, bite point is about halfway through pedal travel, there is a good 3 inches further to press down on the clutch after disengaging, and the pedal feels nice and firm, not spongy.
So I reckon the clutch is working fine.
HOWEVER - the gearbox problems remain. I have taken to double-declutching to get gear changes accomplished.
There is fresh Mobil 1 in there and Molyslip too. I have done around 80 miles with the Moly in so far.
Sometimes I forget to double-declutch and it works without crunching, sometimes it doesn't. Sometimes even with the double-declutch it won't change into the next gear especially going from 4th to 5th after a good booting.
So - what to do next? Are the syncro's shagged (partly or totally?) Can I look inside the box through the oil hole and inspect anything?
So I reckon the clutch is working fine.
HOWEVER - the gearbox problems remain. I have taken to double-declutching to get gear changes accomplished.
There is fresh Mobil 1 in there and Molyslip too. I have done around 80 miles with the Moly in so far.
Sometimes I forget to double-declutch and it works without crunching, sometimes it doesn't. Sometimes even with the double-declutch it won't change into the next gear especially going from 4th to 5th after a good booting.
So - what to do next? Are the syncro's shagged (partly or totally?) Can I look inside the box through the oil hole and inspect anything?
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