Hi guys, as some of you may know, I'm working on an OHV Build Guide... Not just your basic parts/supplier list but rather a more in depth, step by step guide to building an engine for boost, nitrous, or n/a.... and a few people brought up the notion of including transmission mods, which while it doesn't only fall under the OHV Guide, it made me think of making a J-Body Trans Build Guide also, since I'll be writing both as I go through a build of my own.

I'm still tossing around ideas, but right now I'm working with the idea of doing a modified automatic, mainly for consistency and bracket racing purposes.

So, this is my request to any of those who have built up or in some way internally modified their J-body transmission, whether it be auto or stick. Obviously, the Isuzu hybrid stuff will be covered, but since i'm not too familiar with it, you can include that too if you'd like to help me avoid digging through old posts for it.

I'd like to get as much as possible about all of the transmissions, 3spd auto, 4 spd auto, Isuzu 5 spd, getrag 5 spd (did i miss any?). Pics, links, costs, etc... post any info you have, and I'll record it and edit it later as i'm putting the guide together. Even if you think its redundant, post it anyway, I'd rather sift through repeat info than miss something.

Thanks in advance for your help, hopefully we can get this guide thorough enough to at least put to bed a LOT of newbies questions on the issue, as well as even providing new insights to those who are intermediate to advanced in their automotive knowledge.




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said

Dont forget about the NVG T550 swap

i have modded my isuzu tranny and damn, i love it.
I have a 97 z24. what i did is put the 3-4 gear of the 2.2 isuzu tranny in the 2.4 one for closer ratio.
z24 gear ratio:
1st - 3.73
2nd - 2.18
3rd - 1.33
4th - .92
5th - .74
3.94 FDR

2.2 ratio:
3rd - 1.448
4th - 1.027

i cant find the other gear of the 2.2, maybe someone will post this info.

I also put the FDR from the geo storm GSI model (90-92 i think)
FDR: 4.117
now the 3rd and 4th gear from the geo storm is the same ratio from the 2.2, but wont fit, you will have to get these machined to fit right. i just ended up bying another set from a 2.2 this time.
also put to team green LSD.

thats all i can think off!!

will you also need the syncros 3rd and 4th gear.

nope, the 2.4 one will be allright!

Wrench Monkey wrote:Dont forget about the NVG T550 swap

This is what ive been trying to understand.. What is that swap all about?. Can somone fill me in?











~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

Closer gear splits in 3rd & 4th gear means less rpm drop between shifts which keeps the engine in it's peak power band longer accelerating the car quicker.


2000 Z24 5spd header & catback for now.

does anyone know what the final drive is in the 99' cavalier 2.2l 5Spd? where i could get a different differential from to get a better final drive?

I got the Interceptor when I could not find a shift kit and consider it a good upgrade for the auto tranny, next week I´ll be swapping the torque converter and installing a higher stall Yank converter. No messing with the internals yet. I´ll be listening ....

Send me an email..... I've got tons of Isuzu stuff I can share...... and been researching the Getrag stuff.

Never messed with the auto's to much.....

I have done auto - 5 speed swaps, and Isuzu to Getrag swaps..... done the close ratio gear swaps in the Isuzu...... the LSD inserts.....

so send me an email, and I'll send you what I have.




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

yeah im most difinately want that write up! ive never really heard of any real tranny mods basically because ive never looked. But im interested now.


*2012 mazdaspeed3*

talk to Event about the 3-speed.

i had a Saturn LS 4t45e trans and swapped out all the parts to the 4t40e casing to bolt to the ld9. Also had the Yank torque converter put on it along witha external trans cooler from jegs and the auto trans interceptor shift kit. That trans would have been great but something inside failed and caused slipping after 200 miles and three trips down the track. On 6 psi she pulled a 14.0 flat with a 2.0 60' time on 17" nitto 450s. Instead of me diving back into it I found another 4t40e on ebay with 20k on it for 120 dollars. Shipping was 150 but hey for 300 dollars to have a 20k trans was good enough for me. I kept the yank converter out of it and kept it stock. It has lasted so far and i figure if I can get one season out of a 4t40e i am doing ok. Curently at 10+ psi so we will see what happens when I am track abusing her.


01 Z24 Turbo /// First Reflashed Turbo AUTO MMMM YUMMY

there's actually quite a few aftermaket parts available for the 3 sp 3T40/TH125C automatic transmission.

Start with rebuild kits: TranStar Industries makes stock rebuild kits and carries allot of parts (gaskets, seals, frictions and hard parts), but they are meant for stock rebuilds. Alto USA Makes the Red Eagle line for the serious rebuild.

There are three shift kits that I know of: Superior Transmission Makes the K125 Shift Correction Package, is just what it's name implies, but is like a mild shift kit. Trans-Go actually makes a kit (SK125) for this trans, but they don't list it on there web site. It comes with three different separator plates and all the hardware for the up grade. You can either of these kits at your locally owned transmission shops that use the TranStar parts.The third kit is the J-Body Performance Kit, Which looks identical to the TransGo kit. JBP is known for contracting out for their parts and you could get the TransGo kit for approximately $40, as opposed to $130, if you shop around.

The TH125C (and the 4T40E) use a very strong core for their torque converters, the 245mm TC. Many after-market TC builders use these as a base to build their racing converters (for V8s!). This doesn't mean that any mass re-manufacturer is going to be a good TC. In fact most mass re-manufacturers have very poor quality rates. Most of you are probably familiar with Yank Converters, they made an excellent TC for our trannies, but stopped(not enough demand). You can still get one custom built to suit your needs by any reputable High Performance/ Race TC builder. These will typically range in the $200 + range, depending on the builder and features incorporated. These are generally a "you get what you pay for" item. Don't skimp here, these can be probably the biggest gain you can get from an auto tranny.

There is ALOT you can do as far as the gearing goes. First off there are four different chain drive sets you can get: two over drive (32-38 Tooth and 33-37T) sets, one to one and one under drive (33T-37T) . Then there are three Final Drives (differentials) available: 2.84:1, 3.08:1 and 3.33:1. The most common (but not the only) combination found in the J-Bodies is the 33T-37T chain drive and the 2.84:1 FD, this yields a 3.18:1 Effective ratio. Changing your FD to the 3.08:1 would yield a 3.43:1 effective ratio and the changing to the 3.33:1FD would yield a 3.73:1 ratio. For those used to the V8 drive ratios, remember we don't use the 27"+ tires, but 25" stock, which would yield a more effective ratio. The FDs (typically w/ the entire tranny) can be found in salvage yards fairly inexpensively, in many GM and Isuzu FWD vehicles with the 3sp auto. Remember the smaller the motor in the car, the lower (numerically higher) the gear ratio.

Don't forget there are a few different LSDs available, such as the Phantom Grip, the Quaife, Team Green (sorry no link) and Engineered Performance. These all vary in price and performance and can be used with success, in there appropriate uses.( Note: with the PG 904 series you will need to have a grove machined in one of the blocks for the drive shaft retainer lock and the FD locked to the drive shaft and the tranny assembled over the drive shaft.)

I think this is what you're looking for, isn't it?