2000 4.0 Monty, 365k miles, reverse intermittently working

[84FLH]

365,x.. miles. Owned since 225,x.. miles. Never had any trans work except adjust shift linkage cable about 2 months ago. Can't recall why that was done but *think* I was having same trouble with reverse at that time.

Reverse works intermittently. Have to move shift lever from R to D, N, P and back to R for reverse to work. D works fine in parking lot. Haven't driven on the street to see if it shifts okay. Afraid to make it worse by driving on street. Details below. Thanks to everyone for your response. This place can be like the Cavalry to the rescue.

So this just happened this morning: Put in reverse to back out of parking spot, engine rev'd but vehicle didn't move. Put shift lever into P then R, still no reverse movement. Then with motor still running put shift lever from R into N, then P, then back to R and vehicle moved. Drove to another spot in the parking lot 50 yards away, parked, shut off engine. Then started engine and put into R. Vehicle didn't move. Repeated shift lever movements (N, P, back to R) and vehicle moved.

Drove to *another* spot in parking lot. Left vehicle running till reached operating temp on temp gauge. Fluid level checked out okay. Then put vehicle into R and R worked. Backed vehicle up 10 feet. Then put into D and drove forward 10 feet. Repeated same thing 5 times and R worked every time. Twice when put into R I heard "clunk" (like U-joint clunk).

Earliest Saturday appt with local garage is Dec 4. I need Sat appt because I work M-F.

1. Should I take to trans specialist instead of local garage?
2. If so should I take soonest appt avail?
3. Is vehicle safe to drive in forward gear (D, or will driving cause more trans damage?
4. Is vehicle safe to use in R?
5. What could be wrong?

 

[C420sailor]

Sounds like a valve body/servo problem. Although that recent work makes me suspect…

That said…365k for a factory 5R55E is LEGENDARY. I mean top 1% or better. That transmission owes you absolutely nothing. I’d start thinking about getting it a nice rebuild.

 

[donalds]

Time for a rebuild don't drive it imo

 

[84FLH]

Time for a rebuild don't drive it imo

What might happen by driving it? Thank you.

 

[84FLH]

Sounds like a valve body/servo problem. Although that recent work makes me suspect…

That said…365k for a factory 5R55E is LEGENDARY. I mean top 1% or better. That transmission owes you absolutely nothing. I’d start thinking about getting it a nice rebuild.

Thanks, Sailor. I'm pretty sure the linkage/cable repair was because trans wasn't going into reverse. Digging through my repair receipts later to be sure.

Hope that's all that's wrong. Don't want to put $$$ into trans repair on this vehicle. It gets me around okay but needs so much cumulatively that a $$$ repair isn't a wise use of my finances. Then again, used cars are super expensive and I've not found anything I like except for some Broncos and 4Runners on the bringatrailer site. And *those* go for lotta coin.

 

[C420sailor]

You don’t want to drive it if you plan to repair the trans. A small failure rapidly turns into a big failure, and that can make many of the internal parts (and even the case) unusable during rebuild.

Now if you have no plan to rebuild the trans, or sell the vehicle…you can drive it until it fails completely.

I’d start looking for a new vehicle.

 

[84FLH]

You don’t want to drive it if you plan to repair the trans. A small failure rapidly turns into a big failure, and that can make many of the internal parts (and even the case) unusable during rebuild.

Now if you have no plan to rebuild the trans, or sell the vehicle…you can drive it until it fails completely.

I’d start looking for a new vehicle.

Thank you. I understand. Questions:

(1) does that also apply if the problem is caused by linkage/cable being out of adjustment?

(2) what if I drive but don't use reverse?

Thanks again....

 

[84FLH]

Pretty sure this repair was for intermittent not shifting into reverse. It cured the problem until today.

July 22 2021
- Tighten loose bolts on shifter on steering column.
- Lube shifter linkage at transmission.

 

[C420sailor]

That repair isn’t for the actual linkage. Those bolts attach the shift handle itself. That generally doesn’t cause a problem like failing to select reverse or other gears in the middle of the shift pattern—it usually causes a failure to select park. Sometimes the vehicle will roll in park as a result.

To definitively rule out the linkage, you can disconnect the linkage at the trans itself, thoroughly chock the wheels (and have a buddy in the vehicle riding the brake) and manually select gears from underneath. If it still fails to engage then, you know it’s an internal trans issue.