Scroll.....

A little more

Hi,
I bought a t5 for my 89 Firebird a while back and I have a few questions about the speedometer drive.

Here is a pic of the speedometer drive for the 700r4 that was in it.



and speedometer drive gear (700r4)



The speedo drive in the attached pic in my next post is from another T5 transmission I bought for parts.


Are both of these the same Pulse per mile? Does my car have 2000 or 4000 (I think those are the numbers)? Will the one below work in my car? I think I will have to do some speedometer gear changing, correct?


Thanks,
Ryan

Pic.

Well, I just typed a post and accidentally hit the back button.. oh well. I'll sum it up - I had to replace the yellow module that goesconverts the VSS signal for the speedo in my 89 Firebird Formula 305/T5. It ended up that some other car models have different convertors (I think I recall them being called a DRAC?). Anyhow, I believe I found that ours are all the same (not dependent on gearing) - the drive/driven gears compensate.

Anyhow I did some simple math on a calculator to figure out your question of 2000 or 4000 pulses per mile. I got 3888 but that's a bit off - I had the Red 9t drive gear and was going to use a 23t driven for my 3.23s so i wouldn;t have to pull the tail off an already dying gearbox. I know the 9t:23t is a little off but my math is probably pretty good.. So I'd say it probably is 4000 not 2000.

The auto transmission has 17 tooth drive gear, 45 tooth driven, 3.27 rear end gears, and 245/50R16 tires if that helps any.

Thanks for the help,
Ryan

it is 4000ppm