Auto Trans Question

[ABGordon]

I park my truck on the street, facing uphill, and when I shift into drive and take my foot off the brake my truck rolls backwards a significant distance - until I apply the brakes, curse twice, and try it again. One time after driving a short distance it seemed to slip in 1st, one time it semed to slip in reverse, both times right after cold starting. It usually gives kind of a rough jolt shifting into reverse, but I thought maybe this was due to the U-joints (169K on truck, 50K on AT). I checked the AT fluid, it looked and smelled ok, but I am no expert.



When the auto trans went out on my 89 Crown Victoria, I took it into the shop and drove out with a rebuilt one $1,306. 00 later. What are my options here? I will be using this truck for occasional light hauling, and (hopefully) to learn diesel engine mechanics.



Thanks in advance for any help and/or suggestions



-Alan

 

[dan brooks]

Have you tried shifting into neutral for a few seconds before going into drive/reverse? From the factory, the A518 doesn't circulate fluid in park, so giving it a chance to get the juices flowing will probably avoid what you're experiencing.



As far as the jolt going into reverse, it could be U-joints, too much backlash in the rear diff, or even the idle speed set to high. It could also be an internal problem with the transmission, but I'd start by checking the U-joints and pulling the diff cover - unless you've changed the fluid lately it's probably due, anyway, and that will give you a chance to inspect everything to rule out any problems there.



I just had my trans rebuilt a few months ago and installed a Hughes converter -- which is a LOT better than the stock converter -- and the TransGo TFOD-Diesel shift kit, which firmed up the shifts a little and took care of the fluid circulation in park issue. If you only have 50k on your trans the internals should be good, but it wouldn't hurt to have the pan dropped and have a reputable shop adjust the bands and look things over. Just make sure you avoid the "chain" shops and try to find a locally owned business with a good reputation. I'd also avoid letting them use any kind of machine to flush the transmission - after seeing the results of other shops doing it, my friend refuses to use one.

 

[ABGordon]

Are there different or the same considerations in making AT upgrades if you have a 4x2 or 4x4?

 

[dan brooks]

The transmissions are basically the same between 2/4WD, with the only differences being the tailshaft/housing so the transfer case will bolt up, and the speedo sensor is moved to the transfer case output.



I can't think of anything that you would want to do differently as far as mods go. The big issues are the lousy stock converter, converter drain-back/circulation in park (both solved by the shift kit), and cooling, of course. If you don't already have one, you may want to consider adding an under-bed trans cooler, especially if you'll be towing. Those all apply to two and four wheel drives.



EDIT: Just saw the leaky rear main in your sig... gives you the perfect excuse to pull the trans and upgrade the converter while it's out. I'd also install a later model flexplate - the 1st Gen plates have been known to crack. I picked one up from http://www.reliablegoods.com for less than $100.

 

[bgilbert]

Have you tried shifting into neutral for a few seconds before going into drive/reverse? From the factory, the A518 doesn't circulate fluid in park, so giving it a chance to get the juices flowing will probably avoid what you're experiencing.

To all Dodge auto trans vehicle owners: Do this after startup on all your Dodge auto trans vehicles. As Dan said it allows the transmission to circulate fluid plus with the weak converter, it can drain back its fluid and with no fluid there, you get that slipping.

My two autos get started then immediately placed in nuetral, summertime maybe 30 sec or til oil guage stops rising, then put in drive and go, wintertime maybe a little longer idle in nuetral. - Your transmission will appreciate this.

 

[ABGordon]

What a relief. I thought it was a goner.



Yes it is very tempting to consider trans upgrades when time comes to fix rear main seal. Hoping to run it as is for one year since Line-X and ProTech toolbox are on the short-list.



30 seconds in neutral aye!

 

[1stgen4evr]

transmission Prob

Be sure to check the fluid level in NEUTRAL with the engine running, not park. As stated you need to idle a bit before you make it go.



1stgen4evr

James

 

[flightmedic]

I have the same driveline lash as you describe. I laid on the ground next to the truck with a trusted friend in the drivers seat and had him cycle through drive-neutral-reverse. Mine appears to be coming from the transfer case as the output shaft rotates 90 degrees before it appears to take up slack, resulting in a annoying clunk.

It doesn't appear as though your truck is 4wd, but I add this as it was a very informative moment. I noticed that as the truck went into gear, through my periheal vision, the tires were moving simultaneously, and proportionally, to the input yolk of the differential. This along with the fluid being in good shape set my mind at ease that the rear end is still hanging in there.

Extrapolating here, but if there was significant wear in the gears, I would be witnessing something akin to what the transfer case was doing. Something to think about.

 

[ABGordon]

That reminds me of a fill-in-the-blank sentence:



"Funny, all my peripheral vision ever seems to catch is... "