I've got an '83 Trans Am and replaced the original T-5 with one that I think came out of an '87 Camaro, 13-52-066-913. The speedo gear in the tranny is wrong so I thought I'd swap the gears. The bullet and gears are different, the newer trans has a speedo gear with a steel shaft and small white gear on the end, even the bullet is shaped differently than the old bullet. The old unit has the typical grey gear that you see for sale all over ebay, all plastic. The gears aren't the same size so my question is can I swap the steel bullet and gear assembly from one trans to the other? Will they interchange? I stuck the older one inside the newer transmission, it seems to fit but the hold down brackets are different. The older style is a flat plate with a hole, similiar to a TH350. The retaining bracket on the newer bulb/bullet looks like a two-pronged fork. I've read all the forums and some have said the steel shaft is from a truck and incorrect for the production car T-5.
Any help?

 

What you read on the truck forum is BS (NO truck EVER got the F-body tailshaft housing!). I have had 2 T-5s. One was from an 84 and had the bullet with the plastic gear. The one I still have (case was bad on the 84, thought it was fixed but not), is from an 85 Bird with the bullet with the metal shaft and plastic gear. They swap, I promise. The same VSS (I had to buy it since I didn't have a mech speedo in the Bird) fit in both, and I'm pretty sure that at one point or another I've had both bullets together (I seem to never be able to find one or the other or sometimes both at the same time) and the metal shaft can and will go into either. The retainer fork doesn't matter... The hole for the retainer is still in the same spot on the tailshaft housing.

Just make sure that all the gears have the proper number of teeth, and you'll be .

 

Thanks for the help, Maverick. I'll swap them after I get the correct plastic gear for my 3.73s. I know for a fact that the old flat retainer will not fit: when you place it in the slot in the bullet the bolt hole will not line up. Is that normal? I'm not sure the fork-style retainer will work as the two bullets are shaped differently and the early bullet has only one slot. Am I missing something?

I just refaced the speedometer to 160 mph and want to get it calibrated correctly.

Thanks,
Gentry
AutoInstruments Corp.

 

Let me see if I can find both of mine at the same time. They SHOULD be in the bolts bin...

 

Okay, I got them both together...

Mix and match how you need to. However, if you don't have the right gear for either adapter, what I would do is to keep the metal shaft and get a new gear for the end of it. With the cost of plastic as it is, it may be (a bit) cheaper to get the gear without the speedo shaft built in. And besides, the metal shaft is less prone to getting chewed up by the speedo cable (which is steel) than the nylon.

What I would do is to keep the adapter from the late trans as is (adapter, shaft, retainer) if indeed the retainer doesn't work, replace the o-ring, and change the gear if necessary. However, if you already have the right gear and it's the one with the shaft molded into it, just slide the metal shaft out of the late adapter and put the gear into the adapter.

I can't guide you on the retainer since I never got one with the 84 trans... I ended up cutting a piece of the floor pan I cut out to make the shifter hole to make a retainer for the VSS.

 

I bought this car new, had to order it and give a large deposit to make the dealership actually order it, they were afraid they'd get stuck with a manual trans Trans Am that they thought they could never sell. Car was ordered with WS6 so it has 3.73 gears and T-5, surprisingly the transmission had a grey 22 tooth gear in it which appears, from the info on this site, is for a 4.11 rear. I did sell the car for about ten years so it could have been changed but why would anyone deliberately buy the wrong gear? And GM never offered a 4.11 gear on these cars new so they didn't get it out of a junkyard. I don't know if it came in the car from the factory or not.

In any event, I have no reason not to use the steel-shaft unit if I can find the correct gear for the end of it. I don't know if the listed gear ratio/tooth count charts are correct for both large and small gears or not but I don't see any small, replaceable steel shaft gears listed on ebay, is there any information that gives me a part number so i can try to buy it from GM?

Also, the longer nylon shaft speedo gear is much shorter than the steel shaft unit and doesn't stick out of the bullet far enough, or "as far" as the steel shaft. I guess its possible the speedo cable could still grab it but I don't think it will work. Its not the same physical size/length which is very odd. It would probably be easiest if I purchased the correct nylon gear (21 tooth red?) and used the older bullet/gear setup in the newer transmission - if it will fit. It appears to be the same diameter and you've said it would interchange, I could certainly make a new hold down clamp. But it is odd that neither of the old clamps work. Something just doesn't seem right. Knowing how GM or any mass production business operates, they don't change anything if they don't have to. And these are very different. I need to see if the bolt holes are located in the same place, the same distance from the bullet. They must not be or the older clamp would fit both cars. Again, why would they change that?

 

I very much appreciate your help, Maverick.

 

And check out this link:

https://www.thirdgen.org/forums/atta...eedosleeve.png

Is there another seal besides the O-ring seal?

 

I believe the internal bullet seal is a bushing...

I don't have the site listed, but there is a bookmark in the T-5 thread (the one with all the info known to this site, basically) for a gear source. The gear is the same as a TH350 (actually, the whole cable drive assembly and drive gear on the output shaft is the same).

I tried when I did my swap (auto to manual) to get the driven gear from GM. The guy at the parts counter EVENTUALLY (after about a month) got me a DRIVE gear, after having ordered parts for an AUTOMATIC. Basically, I wouldn't go to the dealer. Luckily, I already had the right one sitting on the end of the steel shaft . I suppose it was a good thing that the donor was also a V6 .

I'm not 100% sure on the tooth count... I know that the speedo gears in the auto had the same gear ratio as the rear axle, driven:drive. I believe they were 47:15, but I'd have to dig them out to count again. However, I'm not entirely sure how it works for the T-5 since I know that I have a 7-tooth drive gear and an 18-tooth driven... And yes, my speedo is correct (as verified by multiple radar sources) for a 3.42 rear axle. I would guess that the 21/22 tooth gear is right, but you would need to consult the T-5 guide to be sure. I think that the info is in there somewhere (it's like 11 pages).

 

Thanks again, Maverick. I'll give it a try!
Gentry

 

I got the bullet's swapped today and got the older one installed. As mentioned above the older original-to-the-car assembly came with a grey 22-tooth speedo gear. From what I've read on this site, that gear is for 4.11 gears and the red 21 tooth is for the 3.73 gears, which I have. Is the posted information incorrect? Why would GM install the grey 22 tooth gear from the factory? I think it read correctly all these years. Also, I know I can buy a new O-ring but there seems to be a small, wide, yellow seal that rides on the shaft of the nylon speedo gear. The unit leaks at both areas, of course, they're 30 years old. Where do I get this wide yellow seal?

 

Might want to open the rear axle housing and make sure of what gears are in there before you go any further... It's possible someone either swapped the whole axle or replaced the gears while the car was out of your possession.

As for the seals for the gear, it would probably be better to ask in the FAQ thread. Everything I've told you so far is all I know about the bullet... As I said, I have to run a VSS.

 

I talked to the guy I sold it to today, he had it then sold it back to me. He said he never changed the rear gear and never changed the nylon speedo gear. That seems extremely strange to me, maybe the forum info is incorrect. I'll try it and see what happens.