96 transmission in 1990 Q45

[DrewQ45]

I've located a 1996 Japanese import transmission and am wondering if it can work in my 1990 Q. The parts dealer seems to think so and from the research I've done on here, It should bolt up. What I'm worried about is the OBDII issues. Prior to my transmission failure, I was using a 93' TCU (still have the 90 TCU too). Will I need to get a 96 TCU?

I don't mind opinions but I would like to hear from someone who has actually tried this if possible. Don't want to be suprised after buying this thing.

Thanks....

....Drew.....

[3Q Jay]

ok, sticking to facts and not opinions....you know that you are getting a different gearing than your '90, right?

[DrewQ45]

ok, sticking to facts and not opinions....you know that you are getting a different gearing than your '90, right?

No... I did not know that. I was hoping it would mate up without any major changes.

[3Q Jay]

oh, i didn't say it wouldn't mate up, just that 1st and 2nd are closer ratio [relative to 3rd which is the same], on a 94+ vs. the 90-93.

[Q45denver]

Comparing the 1995 transmission diagram in the shop manual to the 1996, I could see no difference. I have used a 1995 TCU on a 1990 with no problems.

[DrewQ45]

Comparing the 1995 transmission diagram in the shop manual to the 1996, I could see no difference. I have used a 1995 TCU on a 1990 with no problems.

So....I guess I'll definately need a 96 TCU if this is going to work. I wonder how the gearing would feel?

[3Q Jay]

by no means do i claim to be an expert.i don't follow the logic that allows you to conclude that you need a '96 tcm.

the trans itself is dumb. whether from a '90 or a '96 it just has solenoids [5 in total] that respond to signals from the tcm.

[rsiwicki]

the 96 transmission is the same as a 95/94 transmission....the first gear is about 15% difference in gearing so form 0-45mph the car will be much slower and you will need a 94-96 TCU to match the shift points.....all else should be okay. I put in a 92 transmission into my 95 car with no problems after 20,000 miles and have run both a 93 & 95 TCU against the 92 transmission and the 93 TCU is slightly better....but both do just fine.

Search around some more and you will easily find a JDM 90-93 transmission so you keep the same gearing. According to LevelTen.....even the Y33 transmission's match up perfectly to the 90-96 Q45's.....

[RobertsnewQ]

Wait - The 1993 has the SAME gearing as the 94-96 according to my FSM and the 94 FSM. It's only the 90-92s that have the lower gearing. If you're using a 93 TCU you should be good.

[DrewQ45]

I may have to keep looking... I wasn't expecting to make my car slower off the line.

[Q45denver]

You may also want to avoid a 1991's since they had some reliability issues.

[DrewQ45]

I found the transmission specs in the thread below. According the info, the 93 is no different from the 90-92. I am aware that there were some changes in the 91 that I want to avoid. The problem is, how do I tell the years apart? Are there any markings or codes on the transmission to ID the year it was built (if so, where?) or are they all pretty much stamped the same... eg: "RE4R03A".

zerothread?id=25414

Transmission: 90-93

RE4R03A 51x65 transmission 4 speed autoGear Ratio1st 2.784:12nd 1.544:13rd 1.000:14th 0.694:1R200V viscous limited slip differentialFinal Drive Ratio: 3.54:1

94-96

RE4R03A 51x79 transmission4 speed autoGear Ratio1st 2.569:12nd 1.479:13rd 1.000:14th 0.694:1R200V viscous limited slip differentialFinal Drive Ratio: 3.54:1

[RobertsnewQ]

Be careful - that is NOT correct according to the 93 FSM.

My car has the 2.569 gearset according to the specs (and a rough calculation of 1st gear speed vs. RPM).

I've heard talk of two different 1993 TCUs, so maybe one is for the low 1st gear and one is for the high 1st gear. Maybe it's a late/early production 93 thing?

[DrewQ45]

Bumping this thread...

I'm still trying to find out if there are any markings that can be used to ID the model year of Transmissions. Thanks for all the input folks.

[rsiwicki]

you already did find the markings....each transmission has a metal tag attached somewhere with 51x65 or 51x79 stamped into it. I don't remember where to look exactly, but it is there. The trouble with some of the JDM units is that the tag get ripped off or damaged such that it is not readable. Also there are different vent/holes on the case where the torque converter goes that identify what year the transmission is from as well.

Do a search under my discussions with AGM about how to identify the different years of transmission etc. We discussed all of this in great length around April 2004 as I was putting in a 92 transmission into my 95 year car and AGM had done this as well using a 90 transmission and sijko also has done it.

[maxnix]

So....I guess I'll definately need a 96 TCU if this is going to work. I wonder how the gearing would feel?

Well, 1996 is OBDII, so I would look for a 1995 or 1994 TCM.

[DrewQ45]

"you already did find the markings....each transmission has a metal tag attached somewhere with 51x65 or 51x79 stamped into it. I don't remember where to look exactly, but it is there. The trouble with some of the JDM units is that the tag get ripped off or damaged such that it is not readable."

Thx for the advice. I called the supplier and asked him to check the transmission to see what tag it had... Told him I'd only want it if it said "51x65".... He eventually called back to say the metal tag reads "51x05" ... he thinks it's a 94' but is not so sure... Anyone have any idea what model/year that would be? Keep in mind that this is a JDM unit. He also stated that all the Japanese Market Q45 trannys (except the newer models) are the same gearing...something I find hard to believe.