i want to swap gsl-se gears into my car, and am looking for info on where to get the proper speedo gear, any ideas?

 

call any transmission shop for the actual part, they always have ample speedo gears on hand, they might even tell you what you need, as in the # of teeth and size. or someone else on here!

 

I was under the impression that there is only one speedo gear for the 7's. Your error rate should be less than 5%. So if the speedo shows 100 mph, your actual speed will be around 95.

 

i know its s different gear, think its 17 tooth compared to 18 for 3.90 rear.

 

Is it in the Trans? or on the Cable. I have an SE cable is why I ask.

 

its in the tranny where the cable connects.

 

the SE one won't do you any good unless you swap to the larger SE wheels. Stock vs Stock drivetrain in 4th gear at 8k rpm difference is only 3 mph. now if you go to the larger wheels then sure it'll work but that kinda defeats the points of going with the 4.07 b/c you have effectively lowered it back down again with the larger tires.

 

well, i did a search on the differences in tire speeds, and it look like the difference in tire sizes (185/70-13 stock to 205/60-14 gsl-se) will cause my speedo to be 2.1% too slow. now the gearset will increse the amt that it is slow, so wouldn't it make more sense to try to make it a little closer with the proper speedo gear, even if it isn't perfect?

 

2.1 is pretty close. I would think that by having brand new versus bald tires would be almost that much. If you are simply doing the speed limit (by speedo reading), even on interstate you wouldnt get pulled over for speeding.

 

2.1 is jsut the difference in tire size between the two, the higher rear gear will increase that. thats why i'm thinking of getting the correct speedo gear so i am in that 2.1 margin.

 

ahhh, gotcha

 

see my post, it takes into consideration the rear diff ratio. unless your planning on doing 130+ it will be off by less than 3mph. To get my numbers I took 4th gear (1:1 ratio) and plugged in wheel size 185/70r13 with 3.90 rear end. the program then spit out MPH per rpm. I then plugged in 205/60 r14 with a 4.07 rear end. The difference between two plots in 4th gear was 3 mph@8k

By your logic the 14" wheel is 2.1% larger. the ring and pinion of the SE takes 4.1 % more rotation than the stock 3.909 rear. so -2.1+4.1= 2 So grand total of two percent. Your speedo will read 2% too fast, given stock tire size

 

gotcha, thanks for the input. i'd rather it read fast than slow.