I have a 1989 Camaro TBI 5 speed, and the next mod on my list was gonna be 3.73s and a limit slip differential, however im confused on something, currectly I have 3.08 gears which I found out from the RPO number should have known anywayz cuz its a 5-speed car but anywayz. I do not know if my car has 26 or 28 spline axles, since at jegs and summit or what not they say 88 and down is 26 spline and 89 and up is 28. A lot of places have been saying this however, I have a 3rd gen book that says it was in 1990 that chevy upgraded to 28 spline axles. Can anybody verify anything? Thanks in advance.

Jesse Jennings

 

Count them and find out. That's the only way of really knowing.

 

Donno where 2 begin haha.

 

You begin by removing the rear end cover.

You have the changeover year. Nobody can predict what's in it. About 2/3 of them seem to be the 26-spline, especially the real common ratios like yours, and the earlier in the year production. But there's no guarantees. The only way to know is to take it apart and look.

 

I know how to do it just havent done it before, if i open my rear end cover wont all the oil and **** leak out?

 

you will have to pull them out and check them... i made the mistake of assuming that i had the 28s when doing my gear and posi swap... so i had to order some 28s... that is the only way to check... 89s were the wierd year... if i had to guess... i would say that you had 26s...

89gta383 and me found out the hard way... he helped me do my stuff and having to order those axles set us back a week or so!!

 

where did u get them and how much for the 28's ?

 

I hate to do this since I have a set of 28 spline axles for sale for $100 (what I paid for them), but there is two sets on Ebay now for $69.95 per set plus $20 shipping.

http://cgi.ebay.com/ebaymotors/ws/eB...874237863&rd=1


As for checking the spline count, yes you will lose all of your gear lube when you pull the cover. But it's only about $8 for new gear oil anyway.

The procedure to remove the axle is to jack up the car and support it on some SAFE stands, pull at least one rear tire and wheel off, pull the brake drum off that side, then pull the rear sheet metal cover. After pulling the cover you will see the large carrier with a big gear attached to it. With the car out of gear, rotate the gear and carrier until you see a small bolt head in the carrier. I don't remember the size, but use a 6 point wrench and pull that bolt out. After pulling that bolt, there is a large pin that the bolt holds in. Rotate the carrier so you can get the pin all the way out and then push the pin out. Then go to the side where you just pulled the wheel and drum off of and push the axle inward. You will probably hear something drop. That's the c-clip that holds the axle in. If it doesn't drop all the way out, take a magnent and pull the clip out. Then you can slide the axle out and count the splines.

To put the axle back in, just slide it in, rotate it so it engages into the splines in the carrier, install the c-clip and push or pull the axle back out. That will lock the c-clip in place. Then reinstall the pin making sure the hole for the bolt lines up, reinstall the small pin lock bolt and tighten. Then put the cover back on, fill with lube and you are set.

 

that auction, thats for the exact size axles that will fit my 89 camaro 7.5" 10 bolt 2.73 geared thing? I will order one if thats the case. is there anywhere else to get them? like new?

 

New axles are much more expensive. Unless you have drag slicks these will probably do you just fine. And if you do plan on running drag slicks regularly, then a 10 bolt is not the rear for your car.

These axles will fit your 10 bolt AFTER you install the zexel posi from SLP. Right now you probably have 26 spline axles in your car. Like someone else said, probably 70%- 80% chance that they are 26 spline. From the posts I read from people with 89 cars, I've not seen a post yet on here where someone with an 89 had 28 spline axles. But, I could have missed a post.

Now, you have to remember that the $99 zexel from SLP won't bolt in with 2.77 or 3.08 gears. It's a 3 series carrier meaning it will work with 3.23, 3.42, and 3.75's. It may work with 4.10's but I'm not completely sure of that.

What I did was to go get a complete rear end with 3.42's out of a junk yard for $75. Put the zexel and 28 spline axles in and I was set. Also remember you need to re-calibrate your speedo for the new gears. If you are going from the 2.77's or 3.08's you can't do that by just changing the speedo driven gear. It's too big of a jump for just a driven gear change. You will have to change the drive gear on the tailshaft of the trans, or do what I did and buy a speedo correction gearbox for $75. This saved me from pulling the back of the trans apart. The side benefit of this little gear box is that the gear ratio in it is easily and cheaply changed if I ever decide to change my rear gear ratio.

If you do decide to pull the back of the trans to change the speedo gear, here is a link to the hanlon motorsports speedo calibration page. You just type in your gear ratio and tire size and it will tell you what you need for drive and driven gears in your T5.

http://www.hanlonmotorsports.com/t5speedo.asp

As far as installing gears, if you do not have experience at it, then it's best left up to a pro. With the cost of a new set of gears at $175, plus a $100 install kit ,and around $150 to have them put in, I decided that 3.42's for $75 was good enough for me.

If you get another rear with lower gears in it and just swap the zexel in, then expect to pay around $50 to $75 to have it installed by a pro. This is probably the best way for you to go. Then it's a simple (but a little time consuming) job to swap the new rear into the car with only hand tools and a jack with some good stands to support the car. Took me about 4-5 hours with a lunch break and bleeding the brakes. I also replaced my rear shocks with a set of Koni's at the same time.

Overall, this is one of the best mods I've done to my car. There is a world of difference between the 3.42 and the 3.08's. The car starts out easier without having to slip the clutch, and it's much more manageable in parking lots and low speed around town driving in 1st or 2nd gear. And the zexel is a dream come true for these cars. Makes no noise around corners, but when you apply the power it locks up and your gone.

Good luck with your swap.

Dan

 

ok i bought one of those axles off the auction (2). when i get them, im going to get an SLP unit, and some series 3 3.42 gears from richmond. and some of that posi additive stuff, and some regular synthetic gear oil.

anything else i need to change while the guy is in there?
he thinks about $200 to complete the install. sound right?

 

The SLP posi doesn't have clutches, so it doesn't need the additive.

You'll need a kit, with all the bearings and shims and stuff; I'd suggest either getting the kit with the axle bearings and seals too, or getting them separately some other way.

I'd suggest GM Motive gears, unless you drag race the car more or less exclusively. The Richmonds aren't designed for street use, which is part of the reason why they're noisier than some others. Of course, the GM gears aren't desgined for drag racing, so make your choice appropriately. Check www.drivetrainspecialists.com for fairly decent prices and wide availability.

 

I completely agree on the GM gears and putting in new axle bearings and seals. The new axle bearings and seals is cheap insurance in my mind. I also replaced my rear brake shoes and wheel cylinders. (Yes, I have drum brakes in the rear. We can't all be blessed with disk brakes on all four corners)

$200 sounds a little high, but for quality work you get what you pay for. If he is doing the install with the rear still in the car, then it doesn't sound to bad at all. It's a major pain to do it this way.
I guess once you know what you doing and have done a number of ring and pinion installs it becomes much easier. For me it took about 7 try's to get the backlash set just right. But the extra work really paid off. The rear I swapped in with the zexel is much less noisy than the original one I pulled out of the car.

 

<b>The SLP posi doesn't have clutches, so it doesn't need the additive.</b>

wow no? so what actually wears out? i can just use normal synthetic fluid thats it? can it be "fixed" when it wears out?

and.. i dont drag race exclusivlly. GM motive you say? ill check it out.