Recently I swapped a 3.23 rear end into my Trans Am, which originally had 2.73's. I got onto bowtieoverdrives.com and calculated which speedometer gears I would need, and came up with a 17 tooth drive gear and a 43 tooth driven gear (245/50/16 tires). I was expecting to spend about 15 dollars on these two gears, but when I called today to order, the guy told me that I would have to change the speedometer housing in order to run the driven gear, and that it would be an extra 55 bucks. With all the reading that I have done, most people have said its a simple gear swap, and I haven't seen anything about swapping the housing. Do you guys have any experience with this? Any help is appreciated. Thanks!

Chris

 

there are 2 different housings. one housing is for the 35-39 tooth driven gears and the other is for the 40-45 tooth driven gears.

 

Alright - Thanks for the quick reply. Know anywhere that I can get one cheaper than 55 bucks?

 

700R4, 700 Raptor Transmission, 700R4 PATC


these guys have them for $46 for the 40-45 tooth one.
i was just looking, o'reilly's and advance advertise aftermarket ones for about $35 but they have to order them.

 

Thanks a lot!

 

Try your local AC Delco dealer, not Chevy Dealer. I bought a plain housing for about 18.00 and the one for Camaro Police package with speedo output and VSS output for 38.00 at a AC Delco dealer in Chattanooga.
Both gears were abotu 13.00 I think.

 

I saw the same thing, and thought it was a crock, so I just got the gears and swapped gears only - used the existing housing, and I'm having no problems at all 6 months later - my speedo is right on target, and it all works fine - get the gears, and try to swap without the housing first - I couldn't find any reason to spend the extra, and still can't.

 

It's not a crock. There are two diameters of driven gear, and the housings have the shafts offset differently to match.

 

Well, I didn't have any problems with mine, swapped from 2.73 to 3.42, and had to go to the bigger size speedo housing gear, and it all worked fine - All I meant was to save $55 it's worth a shot.

 

Well, I would skip the housing if it's possible, but is there a possibility of breaking the gears if you don't swap the housing? It seems like there has to be a good reason for the two housing sizes.

 

All I know is to try it - if it fits in the housing while it's still in your hand, then it should work fine on the car like mine has for the last 6 months - worse case scenerio is that it won't fit, and you'll wait another week to get the new housing shipped, and have to rejack the car again to get to it.

 

not true. the gear will slide into either housing if it is in your hand. but the wrong housing will not let the gears mesh properly. a 35 tooth driven will slide into a 40 tooth driven when held in you hand. place it into the tranny and it will not work.

 

I'm having a similar issue with a Transmission rebuild where afterward the speedometer gears are no longer meshing. After being screwed up badly by one shop, another is trying to straighten out the first shop mess.

The speedometer was working fine before the first shop worked on the rebuilt. Afterward, it was no longer functioning. Tuning of the EBL system isn't happening because the ECM has no idea the car is moving since no pulse is being seen.
So is this a problem because they might have switched tailshafts? Or switched gears? How are they different to be able to tell them apart?. Which gears belong in which tailshaft?

Thanks to all who take the time to respond.

Dave Buchholz, Rochester NY

 

If the 93 B-body has the same speedo gears-driven VSS style (Not reluctor style) as a 90-92 third gen, the VSS has to match the driven tooth count as mentioned above. So a 43 tooth gear and a 38 tooth gear would be on different VSSs to suit the gear offset, for example.