cubehopper Posted October 25, 2018 Report Share Posted October 25, 2018 After years of clunking from my back end (the cars not mine ),and just recently after a drive with the hood up,hearing a whining from the diff I have decided to strip it down, as its the only thing that hasn't been looked at for years, if ever. Numerous UJs have been replaced along with new driveshafts,new hubs, and diff pins boxed and strengthened, but still the clunking persisted,so I`m pinning my hopes on the diff being worn. First impressions after removing the diffs back cover is that the crown wheel,sun gears and planet gears look in good nick,but there is 10 thou back lash on the crown wheel and when I levered the planet gears towards the sun gears and measured with my DTI on the planet gear there is a huge 35thou movement. Have I finally found my problem,am I right in thinking that the planet gears thrust washers are cream crackered. I intend to fully strip and rebuild the diff replacing bearings seals etc. Does anyone have any views on the diff rebuild kits from Moss,ie are the bearings and seals a good quality. Any advice from anyone who`s tackled the diff rebuild gratefully received. Wish me luck Dave Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 25, 2018 Report Share Posted October 25, 2018 Useful notes here: http://www.74tr6.com/pdfs/Differential.pdf http://bullfire.net/TR6/TR6-38/TR6-38.html http://www.74tr6.com/differential.htm Consider buying only Timken brand bearings. Peter W Quote Link to post Share on other sites
cubehopper Posted October 25, 2018 Author Report Share Posted October 25, 2018 Thanks for those links Peter, closer inspection of the Moss kit shows them to be Timken. When I`ve got it fully stripped I may try some independent bearing stockists Dave Quote Link to post Share on other sites
Sapphire72 Posted October 25, 2018 Report Share Posted October 25, 2018 (edited) Use new diff mount bushings. Good luck. Cheers, Walt Edited October 25, 2018 by Sapphire72 Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 25, 2018 Report Share Posted October 25, 2018 (edited) Beware the collapsible spacer type pinion. This is readily identified by a nylon nut holding the pinion drive flange to the pinion rather than a slotted nut with split pin/wire locking. Setting pinion preload with a collapsible spacer can be a challenger. You can reuse an over crushed spacer by fitting a shim from an MG diff of sorts - I do not know which MG. - or grind off the shoulder and use a solid spacer and shims from an earlier model TR, or Saloon. Worn sun and planet gear thrust washers is an issue. I have a selection of new and used if you know the sizes you need. In thousandths of Inch 0.000" - I do not have a metric measuring stick for curved surfaces. I usually fit a pair of either NOS fibre ones from late TR6 diff or a pair of used equal sized phosphor bronze ones from earlier cars. PM Me if you know what you are after. Crown wheel backlash is the other area of 'clonk' Set this by moving shims on the diff carrier bearings. Cheers Peter W Edited October 25, 2018 by BlueTR3A-5EKT Quote Link to post Share on other sites
RogerH Posted October 25, 2018 Report Share Posted October 25, 2018 22 minutes ago, BlueTR3A-5EKT said: I do not have a metric measuring stick for curved surfaces. Hi Pete, if you have a mm micrometer then you can use a ball bearing to get over the curved surface. Measure the diameter of the BB and then put this on the concave side of the curve. Remove the BB diameter form your measurement. Roger Quote Link to post Share on other sites
Waldi Posted October 25, 2018 Report Share Posted October 25, 2018 I post-ordered new diff bushes 3 years ago, have not driven the car yet, but they are black “rubber”, but almost like plastic. The old metalastic ones were much softer. I would not be surprised if they fail soon (or transmit noise) after commissioning, will then swap to soft PU bushes. So I do not recommend the hard rubber bushes. Waldi Quote Link to post Share on other sites
GT6M Posted October 25, 2018 Report Share Posted October 25, 2018 planets wont mek it wine,n dine. they only come in play whenst corners appear, one side bigger than the other, its roundabouts t,blame try an get the curved,ns as bigg an as tight as will go in they need tapped in wid a punch. as the carriers no smoothe, so a nice fit that lets shafts turn, will be as slack as a laydee of the night in a few miles mek,m really tight, and they be just right after a wee while, DONT use the fibre weshers, they drop t,bits, honest they doo. try an put a few indents in both types, like the g/b thrusts, it,ll hold oil better caution whenst mov,n carrier or pin depth, tget a tolerance.......... they be matched as they are noo, worn to a pattern. { CW/P } moving either one will moer than likely mek things wuss. some times ye just cannae get the backlash doon to factory, but yet have a quiet diff. can ev 10+ thou backlash and its quiet can go to spec, an its as noisey / wine as owt. gotta run it up at speeds wid an electic drill , if it runs quiet, yer ok, if it ..rattles, { yeel soon know !! } its gonna be noisey int car this even though the contact pattern is spot on. if its a collapse spacer, try an mek it a solid,n easy t,doo, and will save quite alot of greif, no to mentionee extra spacers !!!! gud luk M Quote Link to post Share on other sites
cubehopper Posted October 25, 2018 Author Report Share Posted October 25, 2018 Thanks for all the tips . The diff has the slotted nut on the pinion so hopefully then it will be a solid spacer but the car is a 73 CR so it seems that the diff may have been changed at some point . Reading the comments it seems to me that its hit or miss whether you get a quiet clunk free diff even if all the measurements are correct. Dave Quote Link to post Share on other sites
astontr6 Posted October 26, 2018 Report Share Posted October 26, 2018 15 hours ago, cubehopper said: Thanks for those links Peter, closer inspection of the Moss kit shows them to be Timken. When I`ve got it fully stripped I may try some independent bearing stockists Dave Try BRT for bearings as they are one of the largest bearing distributors here in the UK and have branches all over the UK. They don't sell **** bearings, they are usually well known European and Jap. brands. Unfortunately some of the original spec. bearings are now obsolete? Bruce. Quote Link to post Share on other sites
bob buzzard Posted October 26, 2018 Report Share Posted October 26, 2018 If its a solid spacer, make sure the condition of any shim you re-use is spot-on. I once had a shim break out from the pack, lodge in the front roller bearing, and at 50 mph it was like being grabbed by a big hand from behind. Result, pinion welded to inner race - new CW & P required. Quote Link to post Share on other sites
cubehopper Posted October 26, 2018 Author Report Share Posted October 26, 2018 Hi Bob, I was going to replace shims with new as I went along, but after reading about all the potential problems/pitfalls along with the cost of quality bearings/shims/seals, and then at the end of the day it may be down to a certain amount of luck whether the diff is ok or not, I am beginning to question if its worth the hassle of rebuilding it. Rimmers have recon units in stock at £552 ,don't really know the quality of the bearings fitted though. I need to decide whether its cost effective to have a go myself or just scoot off to Rimmers pay the extra money and possibly save myself a lot of grief. I used to be really indecisive but now I`m not too sure Dave Quote Link to post Share on other sites
RogerH Posted October 26, 2018 Report Share Posted October 26, 2018 Hi Dave, I like to do my own Building & Bodging - that way you know how bad it is. I was considering the diff but lack of special tools put me off. have a look here for inspiration on Ed's blog. He even made the special tools. Roger Quote Link to post Share on other sites
Bill Bourne Posted October 26, 2018 Report Share Posted October 26, 2018 Send it to Hardy Engineering, Leatherhead. I've had 2 done there recently. £750 each with new CWP etc etc. (their own) Well pleased. Fit and forget. No connection, just happy at the service. best Bill Quote Link to post Share on other sites
cubehopper Posted October 26, 2018 Author Report Share Posted October 26, 2018 Hi Bill, As we all know its a PITA removing /replacing the diff, so its a job I only want to do once and not repeat, I`m getting too old to be spending hours laid on a cold garage floor with a couple of ton of metal above my head, so I may reconsider my options. Dave Quote Link to post Share on other sites
bob buzzard Posted October 29, 2018 Report Share Posted October 29, 2018 Dave I haven't done much on the forum but am beginning to realise that after 36 yrs of struggle, I might be able to offer just a little advice. Far be it from me to influence your decision.... but, rebuilding diffs is a bit of a black art. I had a whiner once that even baffled the very experienced Pete Cox. I have done one or two using improvised tooling to spread the casing but it was more by luck that it worked out OK. If you can establish what bearings Rimmer Bros are using, I would probably go for the exchange. Best of luck. Quote Link to post Share on other sites
Mike C Posted October 29, 2018 Report Share Posted October 29, 2018 (edited) 4 hours ago, bob buzzard said: Dave I haven't done much on the forum but am beginning to realise that after 36 yrs of struggle, I might be able to offer just a little advice. Far be it from me to influence your decision.... but, rebuilding diffs is a bit of a black art. I had a whiner once that even baffled the very experienced Pete Cox. I have done one or two using improvised tooling to spread the casing but it was more by luck that it worked out OK. If you can establish what bearings Rimmer Bros are using, I would probably go for the exchange. Best of luck. +1. A diff that suddenly locks up on a busy road is no fun at all . Edited October 29, 2018 by Mike C Quote Link to post Share on other sites
cubehopper Posted October 29, 2018 Author Report Share Posted October 29, 2018 Fortune favours the brave, as the saying goes Bob, diff now stripped apart from the pinion which I might not disturb as the bearings seem ok. Does anyone know where to obtain the sun gear shims which are originally brass/bronze as mine are worn, the ones Rimmers/Moss sell, appear on the websites as though they are made from some sort of fibre/plastic, not sure about the durability of those . Dave Quote Link to post Share on other sites
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