88 MJ Speedometer

[rokcrwler]

So recently my speedometer just went out on me. So I bought a new cable and started the install. Tore the dash apart, got the cluster out and cleaned up, ran the new cable and reassembled to no avail. Looked into it more and it turns out where the cable and gear mount in the back of the trans, the gear on the tail shaft is pretty much just a nurle(nearly smooth but like some ratchet handles) So my question is, Where can I find one and how tough is it to install?? Thanks in advance!! :cheers:

[Eagle]

Are you referring to the plastic speedo gear that you push onto the end of the cable and then into the tailshaft housing, or are you saying that the steel (or brass?) drive gear inside the transfer case is trashed?

[rokcrwler]

The plastic gear was in good shape. It is the gear on the tail shaft. It looked like metal of some sort, not brass when I looked inside...

[rokcrwler]

Anybody???

[rokcrwler]

Does anybody have any ideas??

[flint54]

Here are my ideas:

 

If your speedo gear engages anything like mine (I have 4WD with Tcase -but FPL shows to be similar),

the (steel) output shaft has a segment with spiral splines (technically a gear but looks a bit different)

that drives the speedo gear. If your plastic gear is not damaged as you say, it seems very

unlikely (to me) that the output shaft would have gotten damaged. Take a really close look

at those splines (as you probably already have) and see if they actually look to be chewed up in

any way. If they do, you have more problems than just a non-functioning speedo, you have

lot's of metal particles inside the xmission. That's a rebuild, which a lot of folks (especially

me) are unequipped and unqualified to perform. Anything obviously shiny in the fluid?

 

I suspect something else, I suspect an engagement problem somewhere along the line.

 

Coupla troubleshooting ideas:

 

1) Does the plastic gear engage tightly onto its post?

 

2) With the speedo connected, can you create needle motion by spinning the free back end of the new cable?

 

3) With the speedo disconnected, trans end connected, vehicle up on blocks, running and in gear, does

the free front end of the cable spin?

[rokcrwler]

Yes the PLASTIC speedo gear is in near mint condition.

The tail shaft gear (or spiral gear) is somehow ground down and looks knurled. NO more spiral.

The trans shifts AMAZING! Smooth and crisp. Nice red unburnt fluid.

1)Yes the gear engages nicely.

2)Yes I can get needle motion with the new or old cable.

3)Yes I did this and nothing, because the spiral gear is mia..

 

I am just going to buy a used 2wd trans and rob the tail shaft with the gear and install it. I am totally lost as to why it would go out and leave nothing behind. Let alone not chew up the plastic gear. Maybe it was something the previous owner had issues with but never told me. IDK :doh:

 

Oh well, thanks.

 

On a side note, this truck came from Gainsville, FL. I'm the third owner. I have a folder of EVERYTHING done to the truck, with receipts, since mile 25 odo. Second owner only drove it for a couple years, then it sat for 4 years and I picked it up.. Its a sweet little dd thats pretty much rust FREE!!

[flint54]

Well, I'm stumped (not all that hard to do actually), you have a genuine perplexterious mystery.

 

Unless somehow (and not likely based on your provenance comment) that trans had been altered

before you got it. But how? why? Makes no sense at all. Oh well, this presents you the fine

opportunity to get that 6 speed box and 4wd conversion you know you want.

 

Good luck, and if you pull that shaft it sure would be enlightening to see an image of it.

 

You took a FL truck to where?!? That's grounds for flogging! Hope it at least has a good wool blanket.