New speedo gear gone bad

I just replaced my stock 34 tooth count speedometer gear with a 32 count gear. Worked great right after I installed it, for a day. Yesterday it got a little sticky, and then jumpy, and stopped working. Today on my way home from work, my CEL comes on. I pull the speedo gear out, and lo and behold, the damn thing is stripped right in the middle. The gear was like 56 bucks. How the hell did it strip? Didnt even have 10 miles on it! Seems a little pricey..but I'll have to chock it up to improper installation, or something. Wat gets me, it is worked perfect when I tested it! Well, I guess deal with my speedometer being off by like 15 miles an hour at freeway speeds, or pull another 56 bucks out of my...
What could I have done wrong? I indexed it correctly, and it worked!

When you install the gear, the aluminum piece that goes into the tail housing needs to be clocked. It is made so that the gears with different diameters can all be used with this one piece. You probably did not have it in the right position so the teeth were barely contacting the worm gear.

It was oriented in the same position as the one that I took out, which was like 32-38 teeth, and it was worn right in the middle of the gear.

IIRC,there was some info many years back about the indexing being designed "only" for factory available gears.That being said,with any ratios between those numbers you could make your own notch(the housing is eccentric).

Hmm. the housing only has like 4 available 'factory' notches in it.I used the same one that it was set on with the 34 tooth, for the 32 tooth.How in the world would you know how to clock it between the notches, and where it needs to be? The write up seemed so easy..and it was..till I stripped the gear. Beginning to think I should just guesstimate my speed at freeway speeds. I know with my stock gear, I when it says I'm doing sixty, I'm really doing between 75-80. Got pulled over for it once. He let me off...dont want a ticket, but dont want to keep wasting 50 bucks at a time trying to get this right, either.

I reinstalled my 34 tooth count gear. Works as good as it ever did. How would you go about indexing it between the factory adjustments?

i had the same thing happen to mine, it turned out that it had not seated properly when i reeinstalled it due to reusing the old o-ring. it was worn right in the middle just as you describe.

dgrigorenko said:

i had the same thing happen to mine, it turned out that it had not seated properly when i reeinstalled it due to reusing the old o-ring. it was worn right in the middle just as you describe.

Click to expand...

Hmmmm.....I re-used the old O-Ring. Maybe this is the issue... Where did you find your new o-ring at?

You use the same clock position for a 32-tooth and a 34-tooth, as they are grouped into the same range.

i just had mine out due to replacing the clutch, and reused the old o-ring and have had no problems

tjs88xj said:

Hmmmm.....I re-used the old O-Ring. Maybe this is the issue... Where did you find your new o-ring at?

Click to expand...

i picked it up at the dealership for a few bucks

88xj 4.0 31" said:

i just had mine out due to replacing the clutch, and reused the old o-ring and have had no problems

Click to expand...

i have also reused the "old" (being the replacement one that was about 2 yrs old) o-ring with success, but that was when rebuilding the t-case, and it was out of the vehicle, but even then it was really hard to get it to actually seat right without it getting pinched and being slightly out of proper seating. i'm not saying it cant be done, but it does take some effort. putting a new o-ring on was a heck of a lot easier to get the fitment.

tjs88xj said:

I reinstalled my 34 tooth count gear. Works as good as it ever did. How would you go about indexing it between the factory adjustments?

Click to expand...

When I installed my gear in a non new process case, I rotated the collar until the gear hit the worm, then backed of just a little and that happened to be right on the mark for it.