ER34 GTT Nismo GT LSD 1.5 Install Problem

[GoHashiriya]

Hi all,

This morning I took the car to my mechanic to have a new Nismo GT LSD (38420-RS015-BA) installed and he's just contacted me with some issues regarding bolt sizing and flange fitment.

So far he's told me that the bolts that came with the Diff assembly are too small, 12mm vs the 13mm in the car already. And also he cannot get the flanges to fit correctly.

I should mention that the car is a stock 1998 ER34 GTT, however it came as a factory auto and had been swapped to a (cursed) R32 transmission. I wouldn't have thought the diff has been changed but who knows.

As far as the gearing is concerned, I'm certain my ER34 has the AT ratio for final drive as the acceleration is noticeably quicker than another ER34 GTT I've driven.

My question is, do you have any idea what may be happening here? I would have thought there would be no issues installing the Nismo diffs.

There's also the issue that he doesn't speak much English, and I dont speak much Japanese, but he's a nice bloke and has been very helpful so far and dont good quality work on smaller jobs.

[Kinkstaah]

The rear ratio for AT is 4.08 vs 4.111 in Manual. This is utterly un-noticable. (about 1kmh per gear shorter/longer).

Do you really have a R34 GTT standard?

If any of the setup is to suit a N/A in the rear end, you'll have different axles to suit. If it isn't that - For some reason Nismo have two different part numbers for the R34, one for series 1 (98-2000) and one for series 2 (2000-2001)

The one you posted is series2. I am not sure what the differences actually are (or if it is even relevant.) But it is a different part number.

[tsuokun]

Something doesn't add up here.

My car is factory 1999 GTT A/T and it had the 13mm bolts. It had an VLSD.

So this makes me think that if the Nismo P/N really matches and the unit was brand new unopened, that something went wrong somewhere down the line at Nismo (highly unlikely of course). I suppose it would make more sense the other way around: the car had 12mm bolts it and Nismo came with 13mm.

About the flanges: I believe all Nismo LSDs come with the drive shaft ends/stub axles/flanges so unless they don't match the driveshaft bolt pattern (in ER34 this should be 5 in a star shape), there shouldn't be any problems with them.

Note that you cannot use the original VLSD stubs with the Nismo, probably the splines don't match and one of them is too long anyway, so if your Nismo LSD didn't come with the stubs, then no wonder there's trouble.

[GoHashiriya]

2 hours ago, Kinkstaah said:

The rear ratio for AT is 4.08 vs 4.111 in Manual. This is utterly un-noticable. (about 1kmh per gear shorter/longer).

Do you really have a R34 GTT standard?

If any of the setup is to suit a N/A in the rear end, you'll have different axles to suit. If it isn't that - For some reason Nismo have two different part numbers for the R34, one for series 1 (98-2000) and one for series 2 (2000-2001)

The one you posted is series2. I am not sure what the differences actually are (or if it is even relevant.) But it is a different part number.

The acceleration sensation is subjective and if anything irrelevant anyway. 

The part number is correct according to the Nismo catalogue, along with the chassis number and Nissan EPC.

I did get an update that he managed to fit the flanges and have since picked the car up. However, he did use the original 13mm bolts. Unfortunately he didn't get any pics of the work.

He made a comment about how disgusting the insides were and that he was unable to clean up all of the caked oil. The car has about 240k kms on it.

 

1 hour ago, tsuokun said:

Something doesn't add up here.

My car is factory 1999 GTT A/T and it had the 13mm bolts. It had an VLSD.

So this makes me think that if the Nismo P/N really matches and the unit was brand new unopened, that something went wrong somewhere down the line at Nismo (highly unlikely of course). I suppose it would make more sense the other way around: the car had 12mm bolts it and Nismo came with 13mm.

About the flanges: I believe all Nismo LSDs come with the driv e shaft ends/stub axles/flanges so unless they don't match the driveshaft bolt pattern (in ER34 this should be 5 in a star shape), there shouldn't be any problems with them.

Note that you cannot use the original VLSD stubs with the Nismo, probably the splines don't match and one of them is too long anyway, so if your Nismo LSD didn't come with the stubs, then no wonder there's trouble.

I know right, luckily the mechanic was able to get the flanges in today - he told me it was super difficult - and I was able to pick the car up. However, he did not use the 12mm bolts that came with the diff. 

It is odd, and even if Nismo were to have made a mistake - again, highly unlikely - you'd have thought it would have been corrected this far down the line. Where the mistake lies and what I am going to do with these additional bolts, I have no idea. 

[tsuokun]

Well, glad you have your car back on the road again.

I installed an S13 Kaaz 2way on my ER34 and just drilled out the diff centre holes to accept the bigger bolts. I also transferred the ABS rings from the ER34 stubs to the S13 5-bolt stubs.

Going to go Nismo at some point so this was good information. Need to check things carefully.

Cheers.