Speedo dead

[nooblet]

My speedo died completely the other day. There were no signs of it failing, no bobbing or intermittent failing.

So how do I troubleshoot this thing? My odometer stopped working 2 years ago, so I'm guessing its the gauge, but I'd like to narrow it down a little bit since at this point it could be a bad wire, sending unit, gauge, etc...

This is a non-intercooled 4x4, so the sending unit is on the t-case and the gauge is electrical, so don't tell me I have a broken speedo cable

Thanks guys.

Chris

[KTA]

Check the speedo adapter on the t-case. They like to round off ant quit driving.

[nooblet]

Check the speedo adapter on the t-case. They like to round off ant quit driving.

The little two piece box with four screws holding it together? Between the T-case and the sensor?

[KTA]

Yep that is the speedo adapter. I suggest screwing it off both sides(t-case and sensor) and giving it a good inspection.

[nooblet]

Yep that is the speedo adapter. I suggest screwing it off both sides(t-case and sensor) and giving it a good inspection.

Good call KTA. Apparently the output on this little gizmo seized at one time or another because it is frozen. This caused one of the little gears inside to strip the splines of the shaft it rides on (I think??). The input turns freely but the input side of the countershaft (gear reducing part) just spins on the shaft and doesn't turn the output half of the countershaft.

Where do I get one of these little gizmos? Does the dealer even have them?





I screwed the sensor straight into the t-case to make sure everything else is working fine and the speedo works. Does anyone know exactly what the gear reduction is on this thing? it doesn't seem to be a whole lot. I left the sensor screwed into the t-case until I fix the adapter.

Chris

[KTA]

I think Cajun93 here said once they are still available through the dealer. You may want to PM him and check.

[nooblet]

I have to go pick up a part I ordered in a couple of days so I'll just ask them then. Atleast I know what is wrong! Knowing is half the battle right?

Thanks again for the help.

Chris

[nooblet]

I talked to the parts guys at the dealership and learned two things:

1. The parts guys at my dealership are idiots.

2. The parts guys at my dealership like to argue about things which they obviously know nothing about.

They still carry these things, but my parts guys couldn't figure out which one they needed to order with the information I provided them: 3.54:1 axle ratio, Getrag, 315/75/r16 tires. Apparently they need to know how many teeth the speedo gear has (what ever "the speedometer gear" refers to??). Then the "head parts guy" finally told me, "you need to just bypass this adapter and change the speedometer gear in your transfer case". I kindly stated that its not fun to pull the rear output off that transfer case and would rather just buy this adapter. He then turns to the other parts guy and says, "just tell him how much it will cost and he'll leave" (while I'm standing right there). So I rebutted with, "maybe you like taking transfer cases apart, but I don't. Now do you have any clue what your looking for or am I wasting my time here?" He just looked at me and walked away.

Long story short... they have them from $90 to $99, but they have no idea which one to order. Anyone know which one I need, or am I going to be stuck replacing the gear inside the t-case?

Chris

[Ace]

Isn't there a part number or something stamped somewhere on the old one to I.D. it with? Failing that, I'd say pick one and if it's wrong, return it for exhange. There's only two gear options, so with your tires, it will be either a little off or way off. I think that's what he was trying to get at talking about the TC gear. Changing that one is the only way to get a correct speedo readout with oversized tires.

[PToombs]

Why don't you listen to the guys that have "Been There, Done That"?
KTA just said to check with CAJUN93, he works at a dealership and is always willing to help us guys. He will give you the price, availability, and the correct part #.
I guess you call yourself nooblet for a reason.

[nooblet]

Why don't you listen to the guys that have "Been There, Done That"?
KTA just said to check with CAJUN93, he works at a dealership and is always willing to help us guys. He will give you the price, availability, and the correct part #.
I guess you call yourself nooblet for a reason.

He didn't say any of that. He just told me to ask cajun if they sold them. How was I supposed to know he works at the dealership? I will PM him right now.

Chris

[nooblet]

Isn't there a part number or something stamped somewhere on the old one to I.D. it with? Failing that, I'd say pick one and if it's wrong, return it for exhange. There's only two gear options, so with your tires, it will be either a little off or way off. I think that's what he was trying to get at talking about the TC gear. Changing that one is the only way to get a correct speedo readout with oversized tires.

The only ID stamp is what is on that second picture. I thought there were 3 gear options (3.07, 3.55, 4.10) and I told him that, but he had no idea what those numbers meant and also had no idea what he was looking at. He was giving me numbers like .67, .62, etc... I have no idea where he's getting those numbers. I think they refer to how much the adapter reduces the t-case gear, but I'm not sure.

Chris

[PToombs]

I thought you have seen where somebody asks about a part, and he gives the availability, cost, list, etc.
I know KTA didn't say that, I added it in. Sorry if you misunderstood!

Yes, the .67, etc, is the gear ratio.

[Ace]

I didn't notice you have 1990, which still had the 3.07 option...

[CDReyn]

IT sounds like your parts guy was talking about the pinion drive gear inside the transfer case, ...that is available in different gear ratios.
The Gear Reducer( part you are talking about) should be a standard part.
It is a dealer only part las t Iknew and ran around $80.
IF there are a selection based on gear ratio, he can look up the correct one based on your VIN....

sounds like you need a new parts source!

This might help you out some...
http://www.dieseltruckresource.com/dev/ ... p?t=198123