Transfer case VSS gear question

[myf16]

I changed from 18-tooth yellow to 17-tooth white gear and it was chewed up within 300 miles. I have changed back to the old gear. I suppose it's possible I bought the wrong gear but it sure looked right. It was part C3DZ-17271-C. I have a 4WD 96 XLT.

Edited to add: It was the correct part. However for some strange reason it prefers to have fluid in the transfer case. My case was almost dry. Oops. Let's hope the second one survives.

 

[Sip]

Well I was able to find the drive gear and replace it without removing the transfer case. But the new speedometer driven gear is getting chewed up again VERY quickly, within miles. Didn't see any nasty stuff in the fluid I drained out but my hopes are fading fast here. Speedo gears are getting hard to find and I'm suppose to take this thing on a family vacation in a few days. Replaced the sensor just for the heck of it. Don't know if thats going to help at all.

ANY HELP IS APPRECIATED..

Thanks,
Bill

 

[Sip]

I read your rebuild diary(well done!) looking for the answer to a question-
Cruising down the highway and my speedometer dropped to zero.
My VSS gear was worn out so I have new VSS and new 20 tooth gear from Ford. Parts dept at Ford told me to check the VSS gear in the transfercase because it will likely be worn out also. So here's the question-Can I check the transfercase nylon gear without taking it out and is what the parts department told me true in your experience? If it has to be replaced can it be done without pulling the TC?
Also-what causes the VSS to wear out? Failure to change lube? Guilty as charged!
This is on a 1995 4x4 XLT Explorer with 170,000 miles, automatic trans and 4WD "on the fly" on the dash panel. Fluid has never been changed, only topped off occasionally. Not sure which TC I have but can take a look after work tonight. No other known issues with transfer case. One question turned into many. I would appreciate any helpful suggestions.

How did you replace it without removing the transfer case?

 

[jwrezz]

I read your rebuild diary(well done!) looking for the answer to a question-
Cruising down the highway and my speedometer dropped to zero.
My VSS gear was worn out so I have new VSS and new 20 tooth gear from Ford. Parts dept at Ford told me to check the VSS gear in the transfercase because it will likely be worn out also. So here's the question-Can I check the transfercase nylon gear without taking it out and is what the parts department told me true in your experience? If it has to be replaced can it be done without pulling the TC?
Also-what causes the VSS to wear out? Failure to change lube? Guilty as charged!
This is on a 1995 4x4 XLT Explorer with 170,000 miles, automatic trans and 4WD "on the fly" on the dash panel. Fluid has never been changed, only topped off occasionally. Not sure which TC I have but can take a look after work tonight. No other known issues with transfer case. One question turned into many. I would appreciate any helpful suggestions.

Both gears are nylon and just wear out. The TC gear can be seen thru the hole a bit, but a camera scope will show you more. I can tell mine is worn, as the new gear on the sensor still has bouncing speedo. I believe the TC needs to be removed. If not, then at least the rear output shaft area does. I was gonna just drop my TC out for a while as it's not my daily driver. I think now I'm going to bring it with the new gears I got to a local shop.

 

[Sip]

Both gears are nylon and just wear out. The TC gear can be seen thru the hole a bit, but a camera scope will show you more. I can tell mine is worn, as the new gear on the sensor still has bouncing speedo. I believe the TC needs to be removed. If not, then at least the rear output shaft area does. I was gonna just drop my TC out for a while as it's not my daily driver. I think now I'm going to bring it with the new gears I got to a local shop.

I’ve replaced everything and my speedometer needle isn’t moving still on my Ford Explorer 91. I’ve replaced the vss, the sensor on the rear differential, I’ve changed the dash cluster twice, I changed the cable cord, I changed the gear at the end of the vss sensor and still not moving the only thing I haven’t changed was the gear in the transfer case.

 

[jwrezz]

I’ve replaced everything and my speedometer needle isn’t moving still on my Ford Explorer 91. I’ve replaced the vss, the sensor on the rear differential, I’ve changed the dash cluster twice, I changed the cable cord, I changed the gear at the end of the vss sensor and still not moving the only thing I haven’t changed was the gear in the transfer case.

So the 91 has a cable driven speedo, but still has a VSS in the TC as well? But yeah, your process of elimination has landed you with that only option!

 

[1997]

It's been a while, but as I recall: Disconnect battery. Raise, support, & chock vehicle. Mark & remove rear drive-shaft at transfer case, set aside. Remove companion flange from output shaft, discard nut (30MM socket) & small seal, keep washer. Remove VSS. Pull & discard main output seal, gear should be right there.
Best wishes.

Hi, How did you pull the nylon gear off the shaft? It won't move for me and I read somewhere else that the only way is to remove the transfer case?!?!

 

[410Fortune]

I showed you in the other thread how to remove the drive gear

Your control trac t case needs to come out so you can remove the back half and gain access to the nylon drive gear, yes

The pics I showed you are from a 4406 transfer case that has a removable tailhousing
Your t case does not, the speed sensor is in the back half of the case