1995 (mfg Oct 94), 3.2L, 5 speed Isuzu Tranny (not BW), has bottom drain plug and side fill.

Background:
1> Got CEL
2> Code showed Speed Sensor, but Speedo was working fine
3> Few hundred miles later Speedo quits working
3> Removed Sensor, Speedo gear housing/bushing and Speedo Pinion gear
4> Pinion was seized in housing/bushing
5> Replaced housing and gear
6> Test drive showed Speedo jumps erratically
7> Removed new gear to inspect - Showed some damage after just a few miles

OK, now I am getting really worried. If the new gear shows damage then one has to assume the matching gear inside the tranny is bad ? Need reality check from somebody more experienced ... please.

Question:

If removal is required, is it possible to just remove the back section of the tranny and repair this internal gear, or must the whole tranny be pulled? Oh my aching back!

Folks, I sure would appreciate some of you old hands putting your oar in on this problem and your possible solutions. I just picked up this vehicle and really like it as it only has 95,000 miles and is tight and clean. I've done a lot of work already and it would be just about perfect IF I can get this dang speedo problem fixed. All replies appreciated.

I'm wondering if the speedo cable is binding and putting to much pressure on the plastic gear. Can you try to spin the cable with a cordless drill or the likes? You could get a feel for how smooth the cable spins. Just a thought.

Joel

I'm wondering if the speedo cable is binding and putting to much pressure on the plastic gear. Can you try to spin the cable with a cordless drill or the likes? You could get a feel for how smooth the cable spins. Just a thought.

Joel

Hmm, to the best of my knowledge, there is no speedo cable. I was under the impression that the speed sensor sent out pulses to an electronic speedometer. Somebody please correct me if I am incorrect.

Ahhh.. I have not looked at the setup on mine. Didn't know the gear in the tailshaft drove a transducer as opposed to a cable.:banghead: Talk to a reputable transmission shop, maybe they've seen this before & can offer up some info for you.

Joel

Thought I would post the outcome of this situation for future searchers.

When the speedometer gear seized in the speed sensor housing/bushing it also damaged the mating gear on the output shaft of the transmission which, of course, is internal. They are both delrin/plastic gears.

Since I have the Isuzu transmission rather than the Borg Warner, you cannot just remove the tailblock of the tranny to get to this internal gear. So, to fix this damn thing requires a complete R&R of the tranny. I am looking at 600 bucks just to fix the internal speedometer gear so the speedometer will work again.