Jezzer Posted January 8, 2022 Report Share Posted January 8, 2022 Hi guys. I hope you are all keeping well. A quick question for you about my diff.......Ive had my TR6 for about 7 years, I think, I have never driven it and it is undergoing a complete never ending rebuild. I have got to the diff part and am not sure what to do. All of the seals are weeping and as I haven't driven it I am unsure if there are any clonks or whines. Having looked at the brown book it seems that changing the seals is a job I could do, or should I have it checked and refurbed professionally? Thank you, in advance, for your collective brain power. Jez Quote Link to post Share on other sites
RogerH Posted January 8, 2022 Report Share Posted January 8, 2022 Hi Jez, The diff is one of the more awkward things to sort out. The seals are do'able but you may need an extractor for the output seals Why not take it to Hardy Engineering in Leatherhead and then you can get on with something you are more comfy with. Roger Quote Link to post Share on other sites
Mike C Posted January 8, 2022 Report Share Posted January 8, 2022 4 hours ago, RogerH said: Hi Jez, The diff is one of the more awkward things to sort out. The seals are do'able but you may need an extractor for the output seals Why not take it to Hardy Engineering in Leatherhead and then you can get on with something you are more comfy with. Roger +1, there's more to this job than just leaving the diff mounted, sliding the shafts out and then replacing the seals. Quote Link to post Share on other sites
Peter Cobbold Posted January 8, 2022 Report Share Posted January 8, 2022 Assuming you are above stuffing sawdust in the oil to quieten the whine and swelling the seals with additive to cure leaks, its a specialist job. Peter Quote Link to post Share on other sites
rcreweread Posted January 9, 2022 Report Share Posted January 9, 2022 Jez - always worth checking the diff ratio before doing anything else. As standard a UK TR6 would have had a 3.45 ratio but who knows what happened during it's life. Was helping another member tidy up his UK TR6 and it had leaking seals etc - expecting it to be a 3.45, it turned out it was a 4.1! Superb acceleration but poor cruising ability and even worse fuel economy. Export TR6's to the States had 3.7 ratios, hence why it's important to check so you don't renovate a diff which ultimately doesn't suit your requirements. In addition to Hardy Engineering who have a good reputation, you could also try Pete Cox Sports Cars ( https://petecoxsportscars.co.uk/spares-shop/ols/products/tr6-3451-differential ) who always rebuilt my diffs, and I believe have rebuilt units on the shelf to exchange. If you don't know how to check the ratio in the car, jack up one rear wheel, making sure the other can't turn, with neutral selected, and chalk mark the wheel and the propshaft - turn the wheel two full revolutions and count how many times the prop goes around - the ratios will equate as near as dammit to four, three and three quarter or three and a half revolutions to give you your ratio. Hope this helps Cheers Rich Quote Link to post Share on other sites
Jezzer Posted January 10, 2022 Author Report Share Posted January 10, 2022 Thank you for the advice guys. I’ve decided to take it to Hardy Engineering. Quote Link to post Share on other sites
Andy Moltu Posted January 10, 2022 Report Share Posted January 10, 2022 If you know it leaks it would be a false economy not to get it checked out before you put it back. Quote Link to post Share on other sites
ntc Posted January 10, 2022 Report Share Posted January 10, 2022 As for economy I disagree you use more fuel getting up to speed indeed a good friend of mine in a USA spec car on stombergs followed a group of us to Le man and kept pace and used no more fuel than us and there was no overdrive fitted go figure Quote Link to post Share on other sites
michaelfinnis Posted January 11, 2022 Report Share Posted January 11, 2022 15 hours ago, ntc said: As for economy I disagree you use more fuel getting up to speed indeed a good friend of mine in a USA spec car on stombergs followed a group of us to Le man and kept pace and used no more fuel than us and there was no overdrive fitted go figure Maybe the carburettor engine is more economical than the PI? Hard to believe that lower gearing for acceleration saves any significant amount of fuel, whilst higher gearing at steady speeds certainly does. All modern cars have high (overdrive) top gears. Mike. Quote Link to post Share on other sites
John Morrison Posted January 11, 2022 Report Share Posted January 11, 2022 16 hours ago, ntc said: As for economy I disagree you use more fuel getting up to speed indeed a good friend of mine in a USA spec car on stombergs followed a group of us to Le man and kept pace and used no more fuel than us and there was no overdrive fitted go figure Interesting, but hardly a comparison. Tyre size, style of driving, weight of driver and payload etc. John. Quote Link to post Share on other sites
RogerH Posted January 11, 2022 Report Share Posted January 11, 2022 (edited) 16 minutes ago, John Morrison said: Interesting, but hardly a comparison. Tyre size, style of driving, weight of driver and payload etc. John. Quite so John, plus - tyre pressure, tyre make and model, Boot rack etc, headlights, heater fan, radio etc etc binding brakes. Ad infinitiumnium, Roger Edited January 11, 2022 by RogerH Quote Link to post Share on other sites
Peter Cobbold Posted January 11, 2022 Report Share Posted January 11, 2022 The PI is an appalling design with respect to economy. It has to be run rich conitnually at cruise to avoid rattling the pistons when wotting the throttle. The rich cruise mixture made the vac advance redundant. Normally the cruise mxiture would be leaned and the spark advanced ( eg carb vac take-off disy capsule). Carbed 6s should be able to easily beat PI mpg, providing the comp rat is not left at USA specs. Tuning for mpg is a fascinating topic, that has yet to rise to the fore........ Peter Quote Link to post Share on other sites
Tim D. Posted January 11, 2022 Report Share Posted January 11, 2022 1 hour ago, Peter Cobbold said: The PI is an appalling design with respect to economy. It has to be run rich conitnually at cruise to avoid rattling the pistons when wotting the throttle. The rich cruise mixture made the vac advance redundant. Normally the cruise mxiture would be leaned and the spark advanced ( eg carb vac take-off disy capsule). Carbed 6s should be able to easily beat PI mpg, providing the comp rat is not left at USA specs. Tuning for mpg is a fascinating topic, that has yet to rise to the fore........ Peter Agree Peter, and as you know I used an AFR to try and improve the PI economy. It is possible to do quite a lot better than the stock settings but you are always fighting lean pinking at snap WOT. Now, my supercharger setup... thats surprisingly frugal, unless I push it! Tim Quote Link to post Share on other sites
Tim D. Posted January 11, 2022 Report Share Posted January 11, 2022 Interestingly the Stag was generally supplied with a 3.7 diff.. many, like me, have swapped it for a 3.4.. Tim Quote Link to post Share on other sites
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