transmission Swap

[godbody]

I just had a quick question about trannies.

The transmission in my 1990 Q45 went. The car was not coimg out of first gear for whatever reason. Everyone was looking to charge me between $2700- $4200 to rebuild or replace. So rather than being screw'd without the lube, I found one in the junk yard for $300 and a transmission shop to put it in for $400.

The question that I have is there a big difference with the transmissions? My car was made in 9/90 and the one I am putting in was made 4/91. The thing I was told was that the modules had to be changed out and that was it.

But as far as which is the better transmission, does anyone have an idea or is there no difference at all?

[96Qowner]

Nope, they're identical - same gear ratios, same everything.

[Q45tech]

Many of the early 90-91 transmissions failed early on US roads and were replaced under warranty around 50-60k. Various software changes were tried every 6 months to make them function under US drivers. [abusive crank and drive away cold].

Extra cooling was added finally the solution was to start in first gear [1993 models]. 1994 added a milder 1 and 2nd gear to first gear start along with an extra in radiator heat exchanger.

A 1st gear start ecu [1993] and a fully external AT cooler with 30k 2 year total AT replacement has show that when you start with a Nissan remanned you can get 200k service if you are careful and meticulous.

$700 is pretty cheap if you get a years life [12-20k].

I always keep a personal spare ready to swap since my 3rd [ A Nissan Reman] now has 100k.

[oldmako]

Care to comment on quality and lifespan on the later trannys? My 99 has 120K and shifts like silk, but after hanging out on this forum for a few months my sphincter has taken on a bit of a pucker.

I TRY to allow the mother to warm up significantly (at least 1/2 travel from dead cold to normal indication) but sometimes ya gotta go. Plus, I can be Joe Anal, but the PO could have sewn the seeds for early death and there's nothing I can do to prevent that now.

[maxnix]

Regular mechanical fluid exchanges using M1 and a BG machine, pan drop and filter replacement in conjunction with an auxiliary ATF cooler and Q45tech got 173K with .5 second deterioration in shift time.

[qship96]

Regular mechanical fluid exchanges using M1 and a BG machine, pan drop and filter replacement in conjunction with an auxiliary ATF cooler and Q45tech got 173K with .5 second deterioration in shift time.

Just think, if he used Redline D4, and did multiple drain/fills at home, he may have cut that 1/2 second down to 1/4 second,and the transmission may have have been still working fine at 209,000 miles like mine!

[godbody]

Thanks guys, your information was extremely helpful!

[Q45tech]

OH! I've tried the [xxxx- personal opinion] D4 and HighTemp versions of Redline back in 1999............the transmission behaved badly in this case and I opted to remove after 30 days and substitute Mobil 1 both times.

Redline sent me 14 quarts of each to try to get us to stock and use.

Might have been the interaction between Tri mode JWT TCU and D4 not sure just that M1 solved the shudder problem and the transmission went on until mid 2002.

Some trannies are very sensitive to viscosity differences vs temperature.Racing fluids can be nightmares on street in even cool weather!!!!!!!

Things were designed to work with X and trying Y may or may not help especially when things have gotten use to one version.

Selecting a non standard ATF is always an experiment and requires lots of testing to know for sure. The stick-slip vs engagement rpm.

Just like tires you may have to junk [give to relatives] dozens before you find suitable versions.

[qship96]

Sure you didnt try the racing version and the high temp versions of their fluid instead of the D4? The d4 is a dex 3 equivalant and has performed much better for me in the Q transmission than Mobil 1{have used these 2 fluids exclusivly for over 185,000 miles in the same transmission}

[maxnix]

the transmission may have have been still working fine at 209,000 miles like mine!

His was still working well with the new owner some 20K miles later.

He has high standards. Ever time your shifts? Didn't think so. Neither have I.

[Q45tech]

Never heard the final on transmission #2 it had 175k when sold with Mobil 1 to a customer who drove it 20k more and then disappeared. He refused to buy 1st gear start or a ext. cooler?

I used the $500 to buy 1/2 a perfect wrecked Q with a 20k Nissan Remanned [transmission #3] which has 112k currently. This transmission has been run on just Valvoline III conventional ATF flushed every year for 5.5 years.

The point is you can stretch life by just changing ATF frequently whether spending 14 x $5 = $70 x 5 =$350 more for ATF [above basic] adds zero or 100k is unknown. This is something that will take more years to find out.

I have a Nissan remanned sitting waiting for the answer, I'll report in 4.5 more years OR LESS!

[qship96]

Never timed my shifts, but also never needed to, as transmission has never been a problem..... bottom line is under my watch and maintenance routine my ORIGINAL transmission is still operating great in my car at 209,000 miles ...not many here, including qtech, can say that

[maxnix]

I have a Nissan remanned sitting waiting for the answer, I'll report in 4.5 more years OR LESS!

Nothing like data from Dennis!