88V8 Posted August 29, 2008 Report Share Posted August 29, 2008 (edited) It all seems to simple when one begins... have this done by Tuesday, that's last Tuesday, huh. So here I am with the saloon diff that I intend putting into the TR, I've taken the front extension off, and inside is the flanged nose of the pinion shaft, with a castellated nut and thick washer. I'll lay good money that when I undo that nut - easier said than done - I can slip the TR6 front drive flange straight on. But, and here's the nub, it says in the Brown Bible that tightening that nut determines the front bearing preload. At the moment, there's a nut on there with, as I said, a thick washer. So the preload is set. But if I put the TR6 drive flange on there, the preload will change, won't it?? There's a shim pack inside.... it looks as if I have to take the diff apart, get out the pinion shaft, adjust the shim pack to set up the preload... getting way over my head here.... Lakes Tour Friday, can't afford to cock this up. A bit late to be thinking about this you may say. Well, yes. So, before I start to take the perfectly good although not ideal ratio TR6 diff apart - Help, advice please....... Ivor Edited August 29, 2008 by 88V8 Quote Link to post Share on other sites
PILKIE Posted August 29, 2008 Report Share Posted August 29, 2008 Hi Ivor. DONT DO IT!! Best to get the lakes tour out of the way first,and do it as an over winter layup job!! Rushing it will inevitably lead to mistakes happening!!! That gives you more time to sort it out if or when you cock it up! Dave Quote Link to post Share on other sites
piman Posted August 29, 2008 Report Share Posted August 29, 2008 Hello Ivor, it seems that you have a non collapsible spacer differential so there will be no problem with the pre-load as that is set by the shims and spacers already fitted. Just re-tighten to the specified torque 85 - 100Lb\ft. What my ST manual says that all castelated nut\split pinned differentials are shimmed. Some differentials with Nyloc nuts on the pinion are collapsible spacer type, from axle numbers MEC 28316, MF 61622, MG 57569 and MGA 5012 have a collapsible spacer instead of shims. As a matter of interest you can remove this Nyloc nut if you centre punch the nut and pinion shaft and count how many turns of the nut is required to remove it. re-assembly is just replacing it the same number of turns until the two spots are lined up again. (Not to the earlier quoted torque of course) Hope this helps and good luck. Alec Quote Link to post Share on other sites
piman Posted August 29, 2008 Report Share Posted August 29, 2008 Hello Ivor, "I'll lay good money that when I undo that nut - easier said than done" I forgot that bit, as I said earlier the torque on that nut is high, so it is difficult to hold the pinion to undo it. As you don't need the saloon quill shaft, cut a short length off the splined end and weld it to a handle, old spanner etc to use this to hold the pinion while you undo the nut. Needs to be a sturdy job. There is, of course, a special tool for this but where would you find one; that is what I did years ago. Alec Quote Link to post Share on other sites
88V8 Posted August 29, 2008 Author Report Share Posted August 29, 2008 Ha! Excellent. So, one can progress, thankyou very much. And saved me from the error of tightening the flange nut to the TR6 setting of 120lb. Think before I fit the TR6 drive flange, I'll back off the nut and see what torque it takes on my click-off to reinstate its existing setting. After all, 40 years ago torque was torque, eh what? Ivor Quote Link to post Share on other sites
88V8 Posted August 30, 2008 Author Report Share Posted August 30, 2008 Alas. The casing the same? As far as I can see. But the drive flange - totally totally different. The saloon, the shaft much bigger diameter, the splines, different. The TR6, flimsier, thinner, what they call 'value engineering' I suppose. So, no good. And in the process of discovering this I've destroyed the input extension shaft to make the undoing tool - excellent idea, no really - so now I've driven 220 motorway miles to buy a lump of scrap. Heyho. Ivor Quote Link to post Share on other sites
stuart Posted August 30, 2008 Report Share Posted August 30, 2008 Alas. The casing the same? As far as I can see. But the drive flange - totally totally different. The saloon, the shaft much bigger diameter, the splines, different. The TR6, flimsier, thinner, what they call 'value engineering' I suppose. So, no good. And in the process of discovering this I've destroyed the input extension shaft to make the undoing tool - excellent idea, no really - so now I've driven 220 motorway miles to buy a lump of scrap. Heyho. Ivor Ivor Looks like a quick lesson in fitting that LSD that you have tucked away is called for! Stuart. Quote Link to post Share on other sites
BrianC Posted August 30, 2008 Report Share Posted August 30, 2008 The TR6, flimsier, thinner, what they call 'value engineering' I suppose. No, that's a weight-reducing feature in keeping with the TR6's sporting pedigree Quote Link to post Share on other sites
marvmul Posted August 30, 2008 Report Share Posted August 30, 2008 Alas. The casing the same? As far as I can see. But the drive flange - totally totally different. The saloon, the shaft much bigger diameter, the splines, different. The TR6, flimsier, thinner, what they call 'value engineering' I suppose. Ivor When you have removed the saloon drive flange and ALSO the very heavy front bracket , you will find that the TR6 bracket and drive flange can be fitted. I'm not a 100% sure of this, but almost. Quote Link to post Share on other sites
88V8 Posted August 30, 2008 Author Report Share Posted August 30, 2008 When you have removed the saloon drive flange and ALSO the very heavy front bracket , you will find that the TR6 bracket and drive flange can be fitted.I'm not a 100% sure of this, but almost. I thought so. And the bracket can indeed be fitted, but not the flange. At a guess, the saloon flange has a shaft dia of 1.75", the TR6 about 1.25". There are fewer and coarser splines on the TR6 input shaft. I was surprised to find it so, but there we are. Ivor Quote Link to post Share on other sites
marvmul Posted August 31, 2008 Report Share Posted August 31, 2008 Ivor, ' But there we are' : you should go a little bit further : the saloon has an intermediate element, consisting of 2 parts : the first is an axis, taking the flange to the propshaft and at the rear this axis is hollow, with splines : these spines are sliding over a ring : this ring has splines at the outside of course, but also has splines at the inside : these inside splines are sliding over the pinion shaft : this pinion shaft can take your original TR6 propshaft flange!!! Why did Triumph make the saloon set up complicated like this? I suppose to avoid an articulated propshaft... Quote Link to post Share on other sites
Chris59 Posted August 31, 2008 Report Share Posted August 31, 2008 Unfortunatly, my English is not god enough to understand allt your problems, Ivor, but I have already use about 20 saloons "solid spacer" dif on TR's, and "no problemo". Chris. Quote Link to post Share on other sites
88V8 Posted August 31, 2008 Author Report Share Posted August 31, 2008 And lo, the fog of ignorance is illumined by the beacon of knowledge... Thankyou Marvmul. Yes, spline within spline. Never would have guessed. And inside the outer spline, an inner spline which as you say takes the TR6 drive flange. So here are some pics, starting with the two diffs, the TR6 on the left. Just had a heart attack looking at that photo, the driveshaft flanges look smaller on the saloon - went and measured - they're the same... the TR6 diff is balanced on the trolley jack so it's nearer the lens... And here's the extension removed, see the multiple input splines................................... And here's the new oil seal to go in, the inner end of the extension input shaft which was cut off and turned into an undoing tool, and the sneaky spline-in-spline................. Now, yes, I can attach the TR6 drive flange and I have, reinstating the 60 lb torque that was there when I removed it, I guess it's slackened from the original of 85/100 lb due to wear in the bearing, or perhaps was never fully torqued, who knows. Soon when the old oil is out and I've swapped the back covers and it's stopped raining I'll be putting it back in the car, then tomorrow I'll find out - 50 miles to get it properly hot - whether ye olde diff is actually any good or whether I have to put the original diff back in... But what a wonderful example of how not to do things. Do I buy a Haynes manual for the saloon or make any effort to look inside the diff which I could have done two weeks ago? No, I leave it all till the last minute and then ricochet from one problem to another. About the only sensible thing I did was to buy a new input oil seal, you can see it on the left in the last photo, and may I say that there is quite a contrast between the OEM seal in the diff and the new one. The old seal was three-sided, heavy gauge, had to be pried out with hammer and chisel. No chance of removing it with the diff in the car. The new seal is a flimsy thing in which no self-respecting sardine would choose to live - you could get it out with a toothpick. Oh well, mustn't grumble, at least one can easily buy a new seal.. So thankyou once again all, and especially Marvmul & Alec. Stopped raining. Onwards. Ivor Quote Link to post Share on other sites
marvmul Posted August 31, 2008 Report Share Posted August 31, 2008 I thought so. And the bracket can indeed be fitted, but not the flange. At a guess, the saloon flange has a shaft dia of 1.75", the TR6 about 1.25". There are fewer and coarser splines on the TR6 input shaft. I was surprised to find it so, but there we are. Ivor Ivor, the shaft diameter of 1.75" you are referring to, is the ring with the in- and outside splines, I think. The outside splines on this ring fits in the propshaft flange of the saloon(this camshaft flange actually has bearings in the front extension of the diff). When this ring is removed, the TR 6 propshaft flange is simply sliding over the pinionshaft of the saloon differential. Quote Link to post Share on other sites
marvmul Posted August 31, 2008 Report Share Posted August 31, 2008 Ivor, I didn't see your latest comment, when I posted mine : both are 3 : 32 pm. Nice photo's : they are explaining this subject better than a thousand words.. Quote Link to post Share on other sites
Rob Salisbury Posted August 31, 2008 Report Share Posted August 31, 2008 Hey Hey Ivor, thanks for that , now I know why that ex Pi Saloon diff (3.45/1) has been lying around for so long at the bottom of my garage and what to do with it!!......... I've always thought that my uprated 4 pot could cope well with a lower ratio diff, now's the time to find out at zero cost.......... Cheers, Rob Quote Link to post Share on other sites
Tony Millward Posted September 1, 2008 Report Share Posted September 1, 2008 (edited) Hi all, Hope you don't mind me asking but having looked at Ivor's pics, it seems that I also have the same diff that Ivor is fitting. Is the TR6 diff body totally alloy?, cause mine is definately steel (alloy rear part though). Glad you got yours sorted Ivor. Cheers Tony Edited September 1, 2008 by Tonymill Quote Link to post Share on other sites
foster461 Posted September 1, 2008 Report Share Posted September 1, 2008 Hi all, Hope you don't mind me asking but having looked at Ivor's pics, it seems that I also have the same diff that Ivor is fitting. Is the TR6 diff body totally alloy?, cause mine is definately steel (alloy rear part though). Glad you got yours sorted Ivor. Cheers Tony Tony, the body of the diff is cast steel and looks like it could take a direct nuclear hit. Only the rear cover with the mounting fins is aluminum. Stan Quote Link to post Share on other sites
Tony Millward Posted September 1, 2008 Report Share Posted September 1, 2008 Tony, the body of the diff is cast steel and looks like it could take a direct nuclear hit. Only the rear cover with the mounting fins is aluminum. Stan Cheers for that Stan. Looks like mine is 'normal'... Quote Link to post Share on other sites
foster461 Posted September 1, 2008 Report Share Posted September 1, 2008 Cheers for that Stan. Looks like mine is 'normal'... Its amazing these things hold up as well as they do. The pinion and axle seals seem to be the first to go but I dont hear too many issues with bearings or the crown wheel and pinion and this is despite the fact that there is no easy way to drain the oil so it probably never gets changed. The ventilation system is a hole on the top of the rear cover with a split pin inserted. Very hygienic. Stan Quote Link to post Share on other sites
Chris59 Posted September 1, 2008 Report Share Posted September 1, 2008 About Ivor' diff, it isn't a saloon model, I think it is a Stag, if the rear casing is original. The one on a saloon is different, and a one piece alloy part, looking like an original TR6 rear casing (but different). About drive flange, they are all the same, but the one on a saloon gearbox is smaller : why, I didn't have a clue Quote Link to post Share on other sites
88V8 Posted September 1, 2008 Author Report Share Posted September 1, 2008 About Ivor' diff, it isn't a saloon model, I think it is a Stag, if the rear casing is original.The one on a saloon is different, and a one piece alloy part, looking like an original TR6 rear casing (but different). Yes under that muck, the rear casing is alloy. The diff came from the well-stocked shed of a long-standing Triumph Sports Six Club member so I'd be surprised if it's a Stag, but if the Stag diff is also usable in the TR6 then so much the better. Ivor Quote Link to post Share on other sites
88V8 Posted September 1, 2008 Author Report Share Posted September 1, 2008 Wow. What a difference Just went for 25 miles up the A3, make sure everything's OK. Would never have believed such a small change in gearing could make such an impact, after all it only reduces from 120% of standard to 112% of standard, but it's like a different car ! Less need of 2nd & 3rd in restricted zones, picks up better, easily maintains overdrive top on gradients, sat at 80/85mph with good throttle response. Makes the last few days' aggravation well worthwhile. Only trouble is, it's so good I'm not sure now I want to go to a 4.11. The engine seems to hack the 12% overgear with no trouble. There's a 3.69 Nissan R200 LSD.... I suppose I can sell the 4.11 R200 I just bought.... Hmmm, I feel Plan D coming on..... Ivor Quote Link to post Share on other sites
cord Posted September 2, 2008 Report Share Posted September 2, 2008 (edited) ......sorry but what ratio did you change from and to? Edited September 2, 2008 by cord Quote Link to post Share on other sites
88V8 Posted September 2, 2008 Author Report Share Posted September 2, 2008 ......sorry but what ratio did you change from and to? 3.45 to 3.7. Clue to the overgearing - I have 215 x 70 tyres....... Ivor Quote Link to post Share on other sites
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