SkyHarborCowboy

My truck sat for years and I recently got it running. When I select R or D on the lever it randomly does not engage a gear. It just seems like N was selected. The linkage operates normally so I’m guessing something internally. Fluid level is topped off. Any suggestions?

AlpineRAM

How long did you let it idle in neutral before selecting D or R?

Sounds like the drainback valve to me, but since it sat a long time I'd try to drive and see if it unsticks itself.

SkyHarborCowboy

I’ve driven the truck and it runs and shifts fine. It’s an intermittent type of problem. I can drive the truck after starting and then stop to reverse into the driveway and it won’t go anywhere. I’ll try shifting back to drive and it won’t move in drive either. Then I’ll shift it back and forth then it will engage. I probably should just drive it for 30-60 minutes and see if the issue goes away.

AlpineRAM

In that case I'd try lifting the rear axle in a safe manner and "drive" it without load, trying to create as many gearshifts as possible.
Under load it may seem to you that you are in neutral, while being in 1st with insufficient line pressure, burning up your clutch..

Did you check for codes? And did you check the wiring harness from the trans to the PCM- I had rodent damage to this one and a lot of troubles that made me pull my hair..

SkyHarborCowboy

It feels like there is zero engagement not like it’s slipping in an engaged mode. Your idea seems like a good one to try.

There is no maintenance light but I can hook up an obd2 reader. No visible damage to wiring either.

AlpineRAM

OK, these trucks usually do not give you a check engine light when the trans is in trouble..

With the lifted rear axle you'll see if there is no engagement.. not guess or feel.

SkyHarborCowboy

I’ve spent some time driving the truck approximately 150 miles in a mix of city and highway.

This transmission acts acts so weird it’s possessed!

1) Sometimes it’s 100% normal.

2) Sometimes it’s lazy to shift at part throttle.

3) Sometimes it won’t engage either drive or reverse without wiggling the gear lever.

4) Sometimes when you pull up to a light after it functioning normally you can depress the throttle and you don’t move anywhere then it takes off like you just let go of the trans brake on a drag car.

It seems like is more electronic than mechanical but I’m not sure how these transmissions truly function. The issues are so sporadic it would be kinda hard to trouble shoot.

I’ll start by checking grounds and wiring.

Any other suggestions? Anyone know of a thread that describes these issues already?

AlpineRAM

Wiggling the shifter.. key point!

Please check your shifter linkage, especially the bushings, and check your cab mounts.
These trannies do not need electrical stuff to engage 1st or reverse.
Misaligning the gearshift lever on the trans can lead to the problems you have. The lever needs to be in the detent for the gear selected.

SkyHarborCowboy

This issue has me baffled because it wasn’t a problem when I parked the truck 10 years ago.

i monkeyed with the grounds I could find in the engine compartment. I’ll check on the bushings on the linkage tomorrow. The detents definitely are not as positive feeling as my two Ford F350’s that’s for sure.

SkyHarborCowboy

I think it’s down to a line pressure. The linkage seems fine. I’m going to drop the pan and change the filter and fluids. I’m also going to check the cooler lines to see if I can figure out where the leak is at. I’m also adjust the bands while I’m at it.

Is there anything else I can do/check/change while I have the pan off?

SkyHarborCowboy

I changed the pressure solenoid with the GM one from ATS. So far so good. Will do more test driving later in the week. I forgot I also adjusted the bands.

SkyHarborCowboy

I can’t believe it’s been another year since I messed with the truck. Time flies when you have a family.

Ive changed the pressure transducer as well. It’s the same issue.

So I’m still stumped.

AlpineRAM

Did you check the linkage and the cab mounts?

Last week I fixed a 98 with the same problems. Rotted cab mounts and worn shifter linkage bushings.

SkyHarborCowboy

I believe I checked the shift linkage bushings but will check again. I know I haven’t looked at the cab bushings though. I should probably just order a set of each and replace them anyway.

Do you have a suggestion of brand/type for each set of bushings?

In addition, I need to replace my cooler lines. What’s your opinion on a set of steel braided hose and aftermarket cooler as opposed to the stock radiator cooler? Size/brand recommendation?

Thanks,

Joe

AlpineRAM

I would not buy stuff before checking.
To check the shift linkage simply remove the rod from the lever on the transmission, have a helper put the selector into each position, you follow with the selector lever on the trans. You will see if it does not fit right.

Stock cooler size seems good for me, extreme offroading or ultra heavy towing might profit from a bigger one.
If it's just the hoses I get them from an hydraulics shop over here.