Epic Ed

My speedometer cable broke for the second time in three weeks.

First break was shortly after I had my gearing redone to 4.88 front and back. Also added a Detroit soft locker to the rear; TruTrak limited slip up front. I drove it for nealry 3000 miles after the gear change with no major uphill climbs. My first trip up north (to Flagstaff) was a couple of weeks ago. The trip involves some rather long stretches of severe mountain/hill climbing, and this is when it broke. Symptoms were "0" for my speed; no odometer changes; Check engine light turn on; after a while, the O/D light started flickering on/off.

Got it back last week and have been driving around town (both highway speeds and stop & go) with no issues. Today after the first major hill I noticed the speedo needle jumping around quite a bit. By the time I hit my last big hill into Flagstaff the speedometer was done. Crapped out, and the same symptoms as listed above from the first time around.

WTF? The mechanic indicates the first one broke due to a combination of age and high temps since it runs very close to my headers. I have a feeling that it melted through again, but I'm wondering why this only seems to happen after/during long hill climbs?

I included the above info about recent mods only to give you guys something to think about, since the first thing I wonder when something breaks is "what has changed recently." It may not have anything to do with the problem, at all.

Anyone else have major problems with their speedo cable due to heat from the headers? I guess one thing that doesn't make sense to me is I've had the headers on since March -- no speedo issues. If the headers are truely the cause of the failure, why now? And why back-to-back?

Your thoughts?

Thanks -- Ed

Epic Ed

Bump.

Epic Ed

No one has had this problem?

The mechanic took it off today and it's clear that it is getting melted by the headers, despite his efforts to relocate it this last time. Looks like there's just not much play in the cable for relocation options. He's going to wrap it in asbestos to see if that will help. Any other ideas?

Ed

amusement

I haven't had the problem but I know only of 1 person having it.
1989 Toy 4x4 pickup. He had two of the brake within a month. He swapped his instrument cluster and put a new gear speedo gear in the transmission. There's wasn't any problem after it. I think its the speedo gear in the cluster that's the root of the problem. It lacks lubrication or wears out and freezes the gears resulting in the speedo cable being broken.

My thoughts.

Epic Ed

Update --

The mechanic was unable to wrap it in asbestos (not enough pliability), but was able to re-route it. It last a couple of weeks before it went out again. The condition of the cable this time around was fine, but the gear going into the transfer case was stripped. Ordered a new gear, replaced it and...

That was two weeks ago and yesterday it broke again. WTF?!?! I have now broken five speedometer cables in less than two months. WHY? Any suggestions about what might be causing this?

Thanks,

Ed

Epic Ed

If it is the gear cluster, has anyone replaced this in a '95 4Runner? How much might I expect to pay for a replacement part?

tallboy

Ed

Check your rear output flange out of your transfer. If your rear flange that drives your drive shaft has come loose it might cause your plastic speedo drive gear to fail. I have seen this happen before On two diffrent Toyota's. As for your cable breaking from heat of headers mine did this as well. I did buy a diffrent header that was ceramic coated and that cured the problem. You said that your mechanic tried wrapping the speedo cable in header tape. but it was not plyable enough. Why not wrap the headers in header tape to help this problem.


Greg

dajabr

This sounds likely, my speedo gets screaming loud when cold. Will try this eventually and post here.

Ed, does your speedo just start bouncing and then drop to zero wether melted by headers or other?

Epic Ed

Nothing's loose where the cable enters the transfer case that I can see, but then, I'm not entirely sure what I'm looking for to find that flange. Should it be loose to the touch? In other words, would it take some force to move it or is it easy to recognize if it's loose? The last time it failed, it was because the plastic gear at the end of the speedo cable that goes into the transfer case was stripped. It lasted less than three weeks. Not sure if the gear is stripped again (haven't torn it down yet) but I suspect that's the deal again. The cable itself looked to be in good shape. The first two failures, this cable was clearly melted. We re-routed it slightly and it still look to be in good shape from visual inspection. I'll know more on Tuesday.

And, yes, I get the jumpy speedometer needle and then it fails.

Any idea how/why the gear cluster and housing for the speedo cable would cause the gear at the other end of the cable (the one going into the transfer case) to strip? Does it bind and therefore the cable/gear doesn't rotate like it should? It looks like I can get the entire gauge cluster for between $50 - $80 from a junk yard.

Ed

tallboy

Ed


If you gear is stripped, and has done it twice, you need the steel gear and ball that drives it.

Greg

Epic Ed

Cool -- I didn't know a steel gear was available. I'll be sure to get that part if it is stripped again. Thanks for the input.

Ed