Hey Allan...need help with a transmission.

Allan,
I have a 96 Dodge 2500 turbo with a 47RE in it.
Had a ATS HD unit put in it about 5 years ago.
I noticed a week or so ago when in N it felt like it was in D...or at least the RPMs would stay put like it was in gear.
When in P...all was ok. Figured it was a valve sticking...or a blown "O" ring in it. Other than that...it ran like a bandit.
This AM I went to back it out of the barn...and it did not want to move...kinda jerked and finally moved.
I put it in D and it walked right back in like always...just fine.
I still think it's a valve or a blown gasket or "O" ring in the valve body somewhere.
Sure would appreciate any of your knowledge on it.
I know you worked on GM units...but I feel they are all about the same.
I checked the linkage like the book says and it seems ok. I thought a bushing may be worn...but did not see any problems.
Any thoughts?

When you say neutral feels like drive, does it actually want to pull the truck ahead??

How was reverse after the truck ran alittle, did it seem to be normal?

As for blown o-rings or gaskets, probably not it.
The 47RE doesn t use any gaskets or orings in the valve body.

Usually a delay in reverse with a harsh engagement is the result of either converter drainback, a problem with the reverse band or direct clutches, or pump wear.

Depending on what was done for modifications it may or may not charge the torque converter in park. Stock setup, it doesn t. In park, oil just bypasses from the pump back to the pan. Once you move the shift lever out of park to rev the pump has to try and push oil back to the converter, plus engage the rev band and direct clutches. This is where the delay comes in.

Try this, after the truck has sat over night check the trans fluid before you start it. If the converter is draining back, it will be high on the stick. Start the truck, let it idle in neutral for 30 seconds or so, then try reverse.

If it seems OK, then it would point to either a pump issue, pump bushing wear, or a converter problem. A problem with the converter would make the most sense if the RPM are dragging down in neutral.

I ain t no Allan, but hope this helps BW

Hi Bill,

I'm really not much help on the Dodges; just an idea tho:

Ya don't suppose that linkage is coming loose on the inside? Since it only happens in forward vs reverse, that almost sounds like a manual valve problem; like it is "lost" as to it's correct position?

Does it only do it after sitting overnight? Possible drainback like BW says.

Listen to BrokenWrench; he knows his trannys.

Allan

Allan: If you can stand another question, this time about GM products:

I have a '93 Olds Bravada (4.3L V-6, AWD) with a lot of rear-end noise. Wheel bearings have been replaced, but there's a lot of backlash, and I figure the ring-and-pinion has worn out. They tend to do that after 200K+ miles.

I have a '94 Chevy Blazer (4.3L V-6, 4-WD) as a parts vehicle. Is there any reason why the rear differential won't swap over to the Bravada?

What about the front differential? I know the Blazer has a different set-up (i.e., vacuum-operated for intermittent service vs. direct-geared for AWD), but would it work in all-wheel-drive mode?

Thanks for any help you can provide. If you want to shoot me an e-mail, it's open.

-- Maine Fordson

Don't hold a gun to my head, 'cause I've been away from GM for a number of years now.

However, I'm pretty darned sure those two outfits are identical except for that electric operated/fluid clutched transfer case in the Olds.

As for your whine: If it is in one direction only, that is to say, it whines more on deacceleration and kinda shuts up while pulling steady OR VISA-VERSA, it's coming from the ring gear and pinion.

In other words, a ring gear and pinion noise will "change pitch" with differing driving modes.

If the noise is there continually, no matter what and at the same pitch all the darned time, I'd sure suspect those inner carrier bearings. They also go at around 200K miles.

Allan

Thanks for the help...will have to try what you said.
Last week I noticed it trying to pull in N. It would kinda try...but not move.
If I went to P...then N...it would be in N...then gradually the rps drop like it was in D.
Today I did not run it long enough to more than let it roll out of the barn...try R...which seemed like it was fighting itself, and then in D to back in the barn. Pulled in D just fine.
It ran like a bandit last night coming home from work...but that was all in D.
As for the transmission itself...it has every MOD that ATS does. heavy converter, valve body, clutches...the works. Has been trouble free for 5 years. Now it is driving me nuts.
Sure hope it's not that torque converter...that thing cost a bundle.
I tried carefully moving the gear up and down...all to no avail just checking for adjustment.
Thanks for your help...guess I better just take it to a shop.

(Bill46 -- Sorry for hijacking the thread!)

Allan --

Thanks for the reply. The noise I am getting is a hum or growl that is noticeable between 10 and 20 MPH. Less than 10, you can't really hear it, and over 20 there's too much road noise to hear it. It changes with speed, i.e., slows down upon deceleration and speeds up with acceleration. I took the driveshaft off, and there's a lot of backlash evident. Tried replacing the inner and outer wheel bearings, but it didn't make any difference. (A mechanic buddy of mine tells me that it's better to swap the whole differential out rather than try to align those bearings perfectly, which he says is near-impossible.)

Like Gramp always told me, "If it has teats or wheels it'll give ya trouble!"

So, like I mentioned earlier, I have a '94 Blazer for a parts vehicle. I took the rear differential off this afternoon and am cleaning it up to put on the Bravada.

I'm going to try to swap the front differential later. Unfortunately, it was already swapped out before but apparently they put in one with the wrong gear ratio, because subsequently the Bravada started eating prop shafts (at about $350 per copy). The Bravada prop shaft had a double cardon on the back (at the transfer case) and a CV joint at the front differential, because it was constantly in AWD mode. The Blazer I'm using for a parts truck is the one that has the electric/fluid clutched transfer case and a solenoid in the front differential (I think). Notably, the Blazer prop shaft has a double cardon at each end.

The main thing that concerns me is that the Blazer font differential won't be able to stand up to the strain of all-time, all-wheel drive.

Thanks for any thoughts or advice you might have.

Kind regards,
"Maine Fordson"