im interested in putting in 3.42's also but i was wondering how hard it is to put them in, or if i take it to a place how much it would probably cost me for installation?

thanks :hail:

 

There was another post recently in this forum about putting in 3.75 gears. The price would be the same, so the numbers are: Gears: $175, Installation kit $100, Labor $150-$200. So you are $425 to $450 range. Or you can do what I did and go to a junk yard and find a 6cyl. 5 spd. car and get the rear out of it. I got mine for $75 with tax. Put a zexel and 1990 28 spinle axles in and couldn't be happier. I've got $392 in my changover, but that included buying the 3.42 rear end, zexel carrier, 28 spline axles, new axle bearings and seals, shim kit, new carrier bearings, new wheel cylinders, and gear oil .

The difference in price isn't that much, but I've actually got a posi that works now, and the stronger 28 spline axles. And if you can get axles cheap you can probably lower your cost some. There were some on Ebay a few days ago. But check your local wrecking yards first. You are looking for 1990 or newer car to pull the axles out of. You may even get lucky and find a 1990 or newer car with a 3.42 in it. I wasn't so lucky myself. I had to buy two complete rears to get what I wanted.

If you do go this route, don't just assume all 6 cyl 5 spd. cars have 3.42's in them. Pull the cover and count the teeth. That's the best way to confim that they are 3.42's.


And, don't forget you will have to change the speedo gears to correct the error you get when changing rear end ratios.

 

how do u change the speedo gears?

 

First off I need to know what trans you have. T5 stick, or 700R4. With the 350 you have listed in your sig, I will assume you have a 700 R4.

The first step is to find out exactly how far off your speedo is. You might be able to get some part numbers for the correct gears for 3.42's from a dealer, but I took my car to a speedo shop and they ran it on the rollers and got an exact speed reading instead of guessing at it. The cost of running the car on the rollers was $10.

On the back of the 700 R4 trans you will find the speedo cable hookup. If you pull the speedo cable you will then see the speedo cable adapter (for lack of a better name I'll call it an adapter) Anyway there will be a small bolt holding on a locking tab that holds the threaded speedo adapter in the case. You pull that locking tab off and then pull the speedo adapter out of the case. There will be a plastic gear that comes out with the adapter. This is the "driven" gear. Hopefully you are lucky enough that you aren't making a big enough change in the rear gearing that you can change just the driven gear and get your speedometer close. If you can't get enough correction with just changing the driven gear, then you will have to change the speedo drive gear.


Inside the trans is the drive gear. It's just inside the back of the trans inside the tail housing on a 700 R4. The tail housing of a 700 R4 can be pulled with the trans in the car. First you pull the drive shaft (and lose lots of tranny fluid) then take the 4 bolts out that hold the tail housing on. Pull the tail housing and then you will find the drive gear. There is a little clip that holds the drive gear to the shaft. Usually you just tap the drive gear back and it comes off easily. Sometimes it doesn't and you break the clip. You are going to have to go to a speedo shop to get gears anyway, so they should have the clip.

Then just re-install everything with the correct drive and driven gears (use a new o-ring and rear seal for the drive shaft yoke on the tail housing) and you are good to go. (Might want to check the rear bushing in the tail housing also. It locates the front of the drive shaft and if it's worn badly, the rear seal will leak. This is the perfect time to replace it) Don't forget to make sure your trans is full of ATF. If you do have to change the drive gear, this would be a great time to change the fluid and filter in your trans since you wil lhave to drain the trans fluid anyway.


Now there is another way to correct the speedo error. Since I have a T5 and couldn't correct the error without going into the trans to change the drive gear, I got a speedometer gear correction box for $75 including 2 runs on the rollers and making up the correction box and installing it. The little gear box has a great number of gear combinations that are available. And it saved me from pulling my console, shifter, drive shaft, crossmember, draining the trans fluid, and pulling the back of the trans apart. Aother side benifit from getting the gear box is that if I ever do change gears again, I can easily and cheaply correct my speedo error without having to go into the trans. For the $75 I spent on the correction box I felt it was more than worth it not to have to go into the back of my T5 while it was in the car. Hopefully you have a 700 R4 and you won't have to do all this to get your speedo corrected.

Good luck
Dan

 

thanks that helped!

 

You are welcome.