Removing Spitfire Diff
Discussion
Hello all, its great to finally be here on PistonHeads!
I'm wondering if you can help me, I'm currently in the process of removing the diff from my spitfire 1500, I've been following the Haynes manual so far successfully but now I'm slightly stuck!
I've got to the stage where I've opened the road spring access cover, removed the 4 bolts holding the top of the spring plate in place. Now I can't seem to remove the threaded bolt which passes horizontally through the spring securing plate, although I've removed the nut.
For some reason this bolt is not pictured in the Haynes
.
Any ideas on how to remove it, as it’s very hard to access!
Here's the culprit BH605221 (Although mine points in the opposite direction)
Thanks in advance!
I'm wondering if you can help me, I'm currently in the process of removing the diff from my spitfire 1500, I've been following the Haynes manual so far successfully but now I'm slightly stuck!
I've got to the stage where I've opened the road spring access cover, removed the 4 bolts holding the top of the spring plate in place. Now I can't seem to remove the threaded bolt which passes horizontally through the spring securing plate, although I've removed the nut.
For some reason this bolt is not pictured in the Haynes
. Any ideas on how to remove it, as it’s very hard to access!
Here's the culprit BH605221 (Although mine points in the opposite direction)
Thanks in advance!
Leave that nut and bolt alone!
If you manage to get it out at this point you will badger the distance tube and be hunting for a new one. Anyway, it doesn't need to come out.
Dropping the diff by numbers.
1) The diff is an integral part of the rear susspension on a Spit. so make sure the car (at least the rear) is up on axle stands. Take the wheels off as it can generally make life easier.
2) Remove the 4 vertical bolts from inside the car - the GHF223s that it sounds like you've done.
3) Using the '2 nut' method remove the studs from the diff, pulling them up through the spring and out. I think this is where you've got confused - those nuts came off the top of studs that pass through the spring and in to the top of the diff, not bolts coming out of the spring.
4) Under the car place a trolly jack under the diff, just taking it's weight. Remove the 4 nuts/bolts on each of the 2 drive shafts and the prop shaft at the diff end.
5) Drop the exhaust as it's probably going to be in the way.
6) Remove the 2 nuts from the front diff 'ear' supports.
All that's not holding your diff on is the long bolt through the back - 136869
You shouldn't need to remove the spring and certainly not take the spring it's self apart.
If you manage to get it out at this point you will badger the distance tube and be hunting for a new one. Anyway, it doesn't need to come out.
Dropping the diff by numbers.
1) The diff is an integral part of the rear susspension on a Spit. so make sure the car (at least the rear) is up on axle stands. Take the wheels off as it can generally make life easier.
2) Remove the 4 vertical bolts from inside the car - the GHF223s that it sounds like you've done.
3) Using the '2 nut' method remove the studs from the diff, pulling them up through the spring and out. I think this is where you've got confused - those nuts came off the top of studs that pass through the spring and in to the top of the diff, not bolts coming out of the spring.
4) Under the car place a trolly jack under the diff, just taking it's weight. Remove the 4 nuts/bolts on each of the 2 drive shafts and the prop shaft at the diff end.
5) Drop the exhaust as it's probably going to be in the way.
6) Remove the 2 nuts from the front diff 'ear' supports.
All that's not holding your diff on is the long bolt through the back - 136869
You shouldn't need to remove the spring and certainly not take the spring it's self apart.
Edited by //j17 on Thursday 23 November 17:54
Edited by //j17 on Thursday 23 November 17:54
Ideal , Cheers for that step by step guide! It's the first time I've worked on a Spit so there's a bit of a steep learning curve!
Luckily i halted my dismantling procedure and have not removed the spring or any of its component parts
I should be able to remove the diff now, thanks for the info!
Luckily i halted my dismantling procedure and have not removed the spring or any of its component parts I should be able to remove the diff now, thanks for the info!
Whilst you have the diff out you might want to consider a spacer. I refitted the diff on my GT6 last weekend (the carrier shattered bringing me to a standstill), with a 1/2 inch spacer from Canley Classics. It's supposed to lower the car (although to be honest there's no visual difference on mine) but more importantly it gives negative camber to the rear wheels to improve the roadholding. I've not had a chance to give mine a proper run yet but she does feel better through the twisty stuff.
Canley offer 3 options; a 1/2 inch, a 3/4 inch and a full inch. The last is really for track/race use, I went for the 1/2 but after fitting it think I would have been better with the 3/4. Well worth the £20 they cost IMO.
Canley offer 3 options; a 1/2 inch, a 3/4 inch and a full inch. The last is really for track/race use, I went for the 1/2 but after fitting it think I would have been better with the 3/4. Well worth the £20 they cost IMO.
Cheers for the advice, that’s interesting about the spacer, I’ll look into that.
Thought I’d just add a few pics of what's going on:
The diff with most of the oil on the outside
.jpg)
Another of the same
.jpg)
Prop shaft bolts which look new, but I'm having trouble getting them off!
.jpg)
The very oily driveshaft bolts came off easily. I've sprayed lots of WD40 on the prop shaft bolts to help them on their way.
I think I'll get a buddy in to hold the prop shaft still whilst I'm removing the bolts as I can’t get enough leverage on them without the prop shaft rotating!
Thanks for the help so far, i'm slowly getting there!
Don't worry its all supported with axle stands!
Here's the car!
Thought I’d just add a few pics of what's going on:
The diff with most of the oil on the outside
Another of the same
Prop shaft bolts which look new, but I'm having trouble getting them off!
The very oily driveshaft bolts came off easily. I've sprayed lots of WD40 on the prop shaft bolts to help them on their way.
I think I'll get a buddy in to hold the prop shaft still whilst I'm removing the bolts as I can’t get enough leverage on them without the prop shaft rotating!
Thanks for the help so far, i'm slowly getting there!
Don't worry its all supported with axle stands!
Here's the car!
Edited by Nurburgring on Friday 24th November 18:04
Oil on the diff...
OK, have you fiddled with the breather pin yet? If you haven't, fiddle with it now as that could be causing all your problems (though you haven't said what they are so just guessing).
I forget exactly where it is - top, back, left from memory but on the top side somewhere you will find the head of a split pin. This should be loose in a hole and move freely and is there so that, when the diff gets hot and the oil/air inside expands some air can escape to avoid pressure build-up.
The pin often gets clogged with dirt and crud and as a result when the diff gets hot oil is forced out past the nose/driveshaft oil seals.
OK, have you fiddled with the breather pin yet? If you haven't, fiddle with it now as that could be causing all your problems (though you haven't said what they are so just guessing).
I forget exactly where it is - top, back, left from memory but on the top side somewhere you will find the head of a split pin. This should be loose in a hole and move freely and is there so that, when the diff gets hot and the oil/air inside expands some air can escape to avoid pressure build-up.
The pin often gets clogged with dirt and crud and as a result when the diff gets hot oil is forced out past the nose/driveshaft oil seals.
slammedvanman said:
Put the car into gear, it will stop the prop from turning and make it easier for you to undo the nuts
ETA: Nice Spit by the way. Pleased to hear you're getting your hands dirty. Good luck.
ETA: Nice Spit by the way. Pleased to hear you're getting your hands dirty. Good luck.
Cheers, just discovered i'd put it into 2nd where it still rotates, 1st holds it still.
AJLintern said:
Pity you took the driveshafts off first - you could have put the handbrake on to stop the propshaft rotating 
I've put the bolts back into the driveshafts, with the handbrake on and 1st gear engaged it seems to be holding still.
//j17 said:
Oil on the diff...
OK, have you fiddled with the breather pin yet? If you haven't, fiddle with it now as that could be causing all your problems (though you haven't said what they are so just guessing).
I forget exactly where it is - top, back, left from memory but on the top side somewhere you will find the head of a split pin. This should be loose in a hole and move freely and is there so that, when the diff gets hot and the oil/air inside expands some air can escape to avoid pressure build-up.
The pin often gets clogged with dirt and crud and as a result when the diff gets hot oil is forced out past the nose/driveshaft oil seals.
OK, have you fiddled with the breather pin yet? If you haven't, fiddle with it now as that could be causing all your problems (though you haven't said what they are so just guessing).
I forget exactly where it is - top, back, left from memory but on the top side somewhere you will find the head of a split pin. This should be loose in a hole and move freely and is there so that, when the diff gets hot and the oil/air inside expands some air can escape to avoid pressure build-up.
The pin often gets clogged with dirt and crud and as a result when the diff gets hot oil is forced out past the nose/driveshaft oil seals.
Thanks for the advice, i've not checked the breather pin yet - sounds like that could well be the source of the oil leak. I believe a new seal was fitted somewhere recently but this obviously didn't get to the cause of the problem. The main reasons for removing the diff are that it seems to make a lot of whining and grating noises on the overrun. This car belongs to my dad and he wanted someone to do something about the noise, so I'm in charge of fitting a shiney black recon diff
I'm still having a bit of trouble with the propshaft bolts, god knows what they were tightened up with!Waiting for more oil to soak in!
Cheers for the advice so far!
[Edit 19:44] I've now got 3 of the 4 bolts out of the prop, last one is getting rather circular! [/Edit]
Edited by Nurburgring on Monday 27th November 19:43
WoooooooHoooooo, finally got the diff off!! I gave the final prop shaft bolt a good blowtorching and then cooled it with water which loosened it up.
It was fairly tricky to 'land' the diff after unbolting it. It seemed quite happy staying up with no bolts at all. After swinging from the ears and wiggling the whole thing backwards and forwards it came down. I banged my head on an exhaust mount in surprise that it actually moved!
I had a look at the breather; this was 100% clogged with dirt/old oil/rust and provides a likely explanation for the oil leak
Apparently Refitting is the reverse of removal! (remembering to add oil
) Thanks PH'ers for the very useful info!
Edited by Nurburgring on Wednesday 29th November 16:06
Before you fit your reconditioned diff, check that it's easy to turn by hand. It should apparently have about 10 degrees of backlash.
By the way, another useful source of Spitfire info can be found in the Spitfire forum on the Club Triumph website
By the way, another useful source of Spitfire info can be found in the Spitfire forum on the Club Triumph website
AJLintern said:
By the way, another useful source of Spitfire info can be found in the Spitfire forum on the Club Triumph website
Cheers for the link, I’ll head on over there
Got most of it back together now, just having trouble with the rear mount as I can’t seem to align the bolt holes with the mounting? When looking through the mounting holes I can see only half of the hole in the bush.
Is there any way to make some adjustment so that I can slide the bolt through? Currently the diff needs to come down very slightly....
Ideally I would have put the long bolt in first but the diff was too low for it to fit, it now seems to be too high !
Edited by Nurburgring on Sunday 3rd December 20:00
Ahh, seem to remember this being fun...
You need to get the front in before you can get the back in, but you can only get the back in if you haven't got the front in yet!
1) Get a trolley jack under the dif to take the weight and hold it in about the right place.
2) Take off the front mounting nuts/washers so it can move at the front. Don't drop it down though.
3) Push/pull/swear to get the rear bolt lined up and then slide it through.
4) Now the front should go back on OK.
If you let the front drop sometimes (it's a 1970s idea of precision engineering) the fixed bolts won't let the diff swing up as they hit the diff 'wings'. As long as you keep the bolts generally inside the wings it's OK.
Probably clear as mud but... Offer it up and get the rear bolt in first.
You need to get the front in before you can get the back in, but you can only get the back in if you haven't got the front in yet!
1) Get a trolley jack under the dif to take the weight and hold it in about the right place.
2) Take off the front mounting nuts/washers so it can move at the front. Don't drop it down though.
3) Push/pull/swear to get the rear bolt lined up and then slide it through.
4) Now the front should go back on OK.
If you let the front drop sometimes (it's a 1970s idea of precision engineering) the fixed bolts won't let the diff swing up as they hit the diff 'wings'. As long as you keep the bolts generally inside the wings it's OK.
Probably clear as mud but... Offer it up and get the rear bolt in first.
//j17 said:
Ahh, seem to remember this being fun...
You need to get the front in before you can get the back in, but you can only get the back in if you haven't got the front in yet!
1) Get a trolley jack under the dif to take the weight and hold it in about the right place.
2) Take off the front mounting nuts/washers so it can move at the front. Don't drop it down though.
3) Push/pull/swear to get the rear bolt lined up and then slide it through.
4) Now the front should go back on OK.
If you let the front drop sometimes (it's a 1970s idea of precision engineering) the fixed bolts won't let the diff swing up as they hit the diff 'wings'. As long as you keep the bolts generally inside the wings it's OK.
Probably clear as mud but... Offer it up and get the rear bolt in first.
You need to get the front in before you can get the back in, but you can only get the back in if you haven't got the front in yet!
1) Get a trolley jack under the dif to take the weight and hold it in about the right place.
2) Take off the front mounting nuts/washers so it can move at the front. Don't drop it down though.
3) Push/pull/swear to get the rear bolt lined up and then slide it through.
4) Now the front should go back on OK.
If you let the front drop sometimes (it's a 1970s idea of precision engineering) the fixed bolts won't let the diff swing up as they hit the diff 'wings'. As long as you keep the bolts generally inside the wings it's OK.
Probably clear as mud but... Offer it up and get the rear bolt in first.
Cheers //j17!
The garage gave it a bit of persuasion, now its in!
Thanks for all your help!
Sorry to hijack the thread but on the subject of diff's, I want to change the ratio of mine for the trip to Le Mans next year.
When I built the car with a friend many years ago he said that we put one in for acceleration rather than top end but I cant rememeber what it is!
So, if I had a 4.11:1 does this mean 4.11 turns on the input for every 1 turn on the drive shafts of vice versa? I should remeber but cant!
Many thanks in advance and merry christmas!
Stephen
When I built the car with a friend many years ago he said that we put one in for acceleration rather than top end but I cant rememeber what it is!
So, if I had a 4.11:1 does this mean 4.11 turns on the input for every 1 turn on the drive shafts of vice versa? I should remeber but cant!
Many thanks in advance and merry christmas!
Stephen
Do it the easy way - www.mintylamb.co.uk/gearspeed/
Pick what you think you have and play with various 'off the shelf' diff/gear ratios.
My personal suggestion would be to get yer self on overdrive conversion from someone like www.canleyclassics.com - best way to kill 500RPM off your cruising revs
Pick what you think you have and play with various 'off the shelf' diff/gear ratios.
My personal suggestion would be to get yer self on overdrive conversion from someone like www.canleyclassics.com - best way to kill 500RPM off your cruising revs
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