what diff's can i use?

I have a uk manual but it has had the diff refurbed without a lsd. I was wondering if i had to use a uk spec manual diff again. Or would a uk auto, j spec auto, or j spec manual fit. And is there any difference in ratio's? Can anyone help.

thanks mark

It depends which diff you have fitted, the Supra came with 2 diff casing sizes. The UK 6spd was factory fitted with the larger type B diff, similar to the early model J-spec 6spd diff, but with the addition of fittings for the diff oil cooler.

There are pics here of the 2 diffs, TRD sell LSD's to fit each size. The TRD LSD provides much improved traction over the standard factory fitted LSD.

http://mkivsupra.net/vbb/showpost.php?p=2190194&postcount=2

yeh you should have the larger casing if its a uk, so a lager casing will go straight in. if you use the jap spec diff, you need to change a driveshaft and the propshaft too (as well as the diff) i have both types in stock if you need one...

Ok i do have the larger diff. If i was to get a auto lsd for my manual would it fit and be the same final drive?

Ok i do have the larger diff. If i was to get a auto lsd for my manual would it fit and be the same final drive?

uk or jap spec?

if the uk auto lsd, then it fits straight in. not too sure on the ratios but there should be a chart on here somewhere to show the differences.

uk or jap spec?

if the uk auto lsd, then it fits straight in. not too sure on the ratios but there should be a chart on here somewhere to show the differences.

it's a uk spec. If the ratio's are the same i would be intersted in the one you have for sale. Would i be able to collect it from jap show if your going?

Ok i do have the larger diff. If i was to get a auto lsd for my manual would it fit and be the same final drive?

All auto Supras (TT and NA) use the smaller diff casing and LSD, you would need to replace the whole lot including one of the drive shafts and block off the LSD oil cooler. The auto has a different final drive gearing and your UK final drive gear wouldn't swap over.

Best options IMO would be.

1. Find a complete J-spec 6spd diff assembly or 6spd LSD and swap parts over to your UK casing so you can retain the LSD oil cooler. Note the J-spec 6spd final drive gearing is slightly lower, but your UK gearing will swap over onto a J-spec 6spd LSD.

2. Fit a complete UK 6spd diff assembly, although they are probably quite rare.

3. Fit a complete J-spec diff assembly, block off the oil cooler and live with the slightly lower gearing.

4. Buy a new TRD LSD and install in your casing. If you can afford, this would be the best option and give the best results.

Gear ratios for all models here http://www.mkivsupra.net/vbb/showpost.php?p=2361608&postcount=26

Fitting an auto diff will make the rpm in each gear slightly higher than the UK diff. Down side higher rpm for same speed so less mpg and lower top speed. Up side the car accelerates faster.

Sorry but im getting a little confused. hopefully this is my final question. I have the larger diff casing being a uk manual. Would i be able to just swap the whole diff with a uk spec auto diff? Without changing anything else?

One more consideration, the larger 6spd diff *is said* to be stronger than the smaller diff.

Also worth noting, the facelift (96-02) 6spd TT came factory fitted with the smaller diff casing and LSD. Only the early model 6spd TT (J-spec and UK spec) was fitted with the bigger diff.

so is a uk auto diff the larger casing and would fit straight into my uk manual just with a shorter ratio?

Sorry but im getting a little confused. hopefully this is my final question. I have the larger diff casing being a uk manual. Would i be able to just swap the whole diff with a uk spec auto diff? Without changing anything else?

The UK auto uses the smaller diff casing so you would need to also swap one of the rear drive shafts.

• The larger diff has a shorter drive shaft on one side (can't remember which off the top of my head).
   
   
  
• The smaller diff uses drive shafts of equal lengths each side

Not sure about the LSD cooling fittings and whether these are the same on the auto and manual diffs, CW may know.

so is a uk auto diff the larger casing and would fit straight into my uk manual just with a shorter ratio?

No the UK auto uses the smaller diff, see explanation above.

Sorry but im getting a little confused. hopefully this is my final question. I have the larger diff casing being a uk manual. Would i be able to just swap the whole diff with a uk spec auto diff? Without changing anything else?

yes as they are the same size.

It depends which diff you have fitted, the Supra came with 2 diff casing sizes. The UK 6spd was factory fitted with the larger type B diff, similar to the early model J-spec 6spd diff, but with the addition of fittings for the diff oil cooler.

 

There are pics here of the 2 diffs, TRD sell LSD's to fit each size. The TRD LSD provides much improved traction over the standard factory fitted LSD.

 

http://mkivsupra.net/vbb/showpost.php?p=2190194&postcount=2

This is interesting

I took my car to Whifbitz for a timing belt change and a service he said that i and a different diff which i was shocked to here.It was done over in Japan, Must have a look to see what one i have...

No the UK auto uses the smaller diff, see explanation above.

no it dont. the uk models all have the larger diffs.

the j spec tt have smaller diffs (same size as the na)

the 6 speed early jspecs have the larger diff.

no it dont. the uk models all have the larger diffs.

Hmmm.... I could be wrong, but I'm fairly certain that I've supplied a TRD LSD for an auto UK and it was the smaller diff, although I'm not as familiar with the UK spec, so I stand to be corrected. The EPC would confirm either way, although I don't have access here at moment.

the j spec tt have smaller diffs (same size as the na)

 

the 6 speed early jspecs have the larger diff.

Yes agree, only early J-spec 6spd TT had the larger diff.

yeh all the uks had the larger diffs apparently. i know all the breakers ive had have had them anyway (and the ones ive had and sold etc)

they also had the coolers on them all too. the jspecs never had the coolers on any model afaik. never came accros a jspec with a cooling system on it...

Hmmm.... I could be wrong, but I'm fairly certain that I've supplied a TRD LSD for an auto UK and it was the smaller diff, although I'm not as familiar with the UK spec, so I stand to be corrected. The EPC would confirm either way, although I don't have access here at moment.

 

 

 

Yes agree, only early 6spd TT had larger diff.

yeh all the uks had the larger diffs apparently. i know all the breakers ive had have had them anyway (and the ones ive had and sold etc)

 

they also had the coolers on them all too. the jspecs never had the coolers on any model afaik. never came accros a jspec with a cooling system on it...

If that's the case I've learnt something new then today

Sorry Mark for confusing the issue, looks like the UK auto diff would be a straight swap, only difference would be the gearing.

they also had the coolers on them all too. the jspecs never had the coolers on any model afaik. never came accros a jspec with a cooling system on it...

Yes the EPC doesn't list the diff cooler on the J-spec, only the European and US models.

thanks for everyone's help.