Dr_Doom Posted January 30, 2007 Share Posted January 30, 2007 Ok, I’ll make this as simple as possible. The diff broke in my 1996 Manual NA Supra. I got a replacement Diff from a 1996 Manual NA Supra but when we changed it over the flanges where the half shaft join were different. The old diffs were narrow & the new diffs were about an inch wider. We had to swap the stub shafts around so that the diff would fit. 24hrs after, the new diff broke (pinion bearing collapsed) so whether or not it was due to this I’m not sure. Big Question - Is there anyway to tell the difference between a Manual NA and Auto diff without taking the casing apart and counting the teeth? Did they have different size flanges? I’m starting to think that my car may have been fitted with an Auto diff at some point. I’m going to look at a NA Manual diff at a breakers this afternoon and don’t want to buy the wrong thing. Is it ok to use either Auto or Manual diff or will this put more strain on the gearbox etc?.. I'm confused! Thanks for your help, Rob Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted January 30, 2007 Author Share Posted January 30, 2007 forgot to mention that i know Auto & Manual Diffs have different ratios & effect acceleration, top end etc... I just can't work out which one i had in the car originally Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 30, 2007 Share Posted January 30, 2007 Diffs are a nightmare, I get confused myself with all the various ones. Terry seems to have a good handle on ID'ing them and suchlike. I prefer to get the customer to order LSD kits themselves, if it doesn't fit *HE* gets to eat it, not me I can't see any correlation between output shafts and pinion bearing collapse unless the thing created shrapnel within. Quote Link to comment Share on other sites More sharing options...
bondango Posted January 30, 2007 Share Posted January 30, 2007 Ok, I’ll make this as simple as possible. The diff broke in my 1996 Manual NA Supra. I got a replacement Diff from a 1996 Manual NA Supra but when we changed it over the flanges where the half shaft join were different. The old diffs were narrow & the new diffs were about an inch wider. We had to swap the stub shafts around so that the diff would fit. 24hrs after, the new diff broke (pinion bearing collapsed) so whether or not it was due to this I’m not sure. Big Question - Is there anyway to tell the difference between a Manual NA and Auto diff without taking the casing apart and counting the teeth? Did they have different size flanges? I’m starting to think that my car may have been fitted with an Auto diff at some point. I’m going to look at a NA Manual diff at a breakers this afternoon and don’t want to buy the wrong thing. Is it ok to use either Auto or Manual diff or will this put more strain on the gearbox etc?.. I'm confused! Thanks for your help, Rob Did you remove the pinion at all?? or did you just tap out the stubs? You cant just slap in the pinion or stubs unfortunately. The stubs must be properly reshimed up, and the pinion needs a new crush washer and torque procedure when re-installing. Easiest way is to get the Diff code from your car, and find a breaker with a whole car to find the exact Diff. As you say it was a 96 diff, but may have came from a VVti N/A (end of 96) with the 6 speed box?? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 30, 2007 Share Posted January 30, 2007 Diffs are a nightmare, I get confused myself with all the various ones. Terry seems to have a good handle on ID'ing them and suchlike. I prefer to get the customer to order LSD kits themselves, if it doesn't fit *HE* gets to eat it, not me I can't see any correlation between output shafts and pinion bearing collapse unless the thing created shrapnel within. EDIT: I assume you did, as Bondango mentions, reshim the stub shafts? These shafts and their bearings control the offset and preload on the crownwheel. Get this wrong and nasty things can happen.. Some people just slap in TRD LSD's without checking tooth contact and bearing preload. production tolerances are such that these need fully checking when installing, and shimming to suit. Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted January 30, 2007 Author Share Posted January 30, 2007 Hi, thanks for the info. The diff is an NA open type but I’m sure this won’t make a difference. When the garage fitted the new diff only the stub shafts were changed as there was about an inch difference in size. The pinion wasn’t touched. As for re-shimming the stub shaft, I’m guessing this didn’t happen but I’ll check with the garage in the morning I’ve picked up another manual diff from a breakers today but this also has the wrong size flanges. This has led me to believe that my car must have had an Auto diff fitted for whatever reason. I’ll need to fit the smaller flange stub shafts to the new manual diff to make it fit so I guess they’ll need re-shimming first?.. Is this a difficult / specialist job? If so, it might be worth trying to find an NA Auto diff instead. This is a nightmare as it will be the third I’ve bought in a week!... Thanks, Rob. Quote Link to comment Share on other sites More sharing options...
bondango Posted January 31, 2007 Share Posted January 31, 2007 Rob, This is the only rebuild info i have http://supras-ireland.net/manuals/Workshop%20Manuals/Supra%20MK4/09%20-%20Axles/Differential%20&%20axle%20shaft.pdf Im doing a supra mk2 open diff to LSD conversion for someone at the moment and its an absolute ball breaker, looking at the mkiv Diffs, its nearly the same amount of greif. Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted January 31, 2007 Author Share Posted January 31, 2007 Thanks for the warning I'm thinking that if the stub shaft flanges are different sizes on the auto & the manual then it's likely that the half shafts are slightly different lengths too. I'm clutching at straws at the moment but i've managed to find 2 half shafts that match up to the Manual diff. I'm hoping that if i swap these over, the new diff should fit without having to swap the stub shafts. What do you think? Is there anything else that is likely to be different?.. Surely the whole back subframe/axle setup etc isn't totally different between a manual & auto?... Thanks, Rob. Quote Link to comment Share on other sites More sharing options...
Guest DaveH Posted January 31, 2007 Share Posted January 31, 2007 Just so I'm understanding, you are saying that the part that I'm holding in this picture is a different length? If so, can you tell what part is longer/shorter? There isn't any shimming to be done when changing this part. http://www.boostwerx.com/pics/LSD/LSD02.JPG Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted January 31, 2007 Author Share Posted January 31, 2007 Yes Dave, that's right. Thanks for the reply. Here is a photo of the one i took out of the NA Manual diff. Notice how the flange is wider? The shaft that fits into the diff is the same size though. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 31, 2007 Share Posted January 31, 2007 Just so I'm understanding, you are saying that the part that I'm holding in this picture is a different length? If so, can you tell what part is longer/shorter? There isn't any shimming to be done when changing this part. http://www.boostwerx.com/pics/LSD/LSD02.JPG If you JUST change the shafts no shimming is needed, if you cahnge the side plates (bolted to the diff case with the ring of rusty bolts, each side), these are shimmed to move the bearings within in and out. Quote Link to comment Share on other sites More sharing options...
SatSport Posted January 31, 2007 Share Posted January 31, 2007 to Dave_H Didn`t you fit the auto tt lsd diff (3.77) into the std N/A casing? Thinking of doing this myself, any disadvantages? Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted January 31, 2007 Author Share Posted January 31, 2007 Hi. Thanks to everyone for the advice. I'm going to pick up a pair of half shafts tonight that should be the right match for the diff. I think this is the most sensible idea as i won't have to modify the diff. If this fails or doesn't fit at least i know that i can get away with swapping the stub shafts around Quote Link to comment Share on other sites More sharing options...
dini_the_owl Posted January 31, 2007 Share Posted January 31, 2007 "atm the most depressed" you still have a smile on your giff picture mate cant be that bad! let me know when you need photoshop...... Quote Link to comment Share on other sites More sharing options...
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