98 Wrangler (Trans issue when Cold)

[my98jeep1970]

Hi Folks, I have a 98 TJ Wrangler (4.0L). When I first start the Jeep and go to drive the trans slips for a few then pops back into gear.. This ONLY happens once when the engine is just warmed up. The rest of the day its fine. I have checked the fluid and its still nice and red color... Any suggestions on what this could be? Thanks!

 

[Jester32]

Check the fluid before you start it. If its way over filled the torque converter is leaking Down.

 

[Jester32]

Assuming its an auto

 

[my98jeep1970]

Yes, its an Automattic.. So, check when engine is off.. I was alway told to check when engine is on with the exception of our Honda.. I will do that.. Now if its not over do you have any other suggestions? Thanks!

 

[Jester32]

Yup. This is only to see if the torque is leaking down. It has to be checked when it would act up like first thing in the morning. With the veh off. If its over by more than a quarter inch than you could have torque converter leak down. If its ok I will carry on down the chart.

 

[my98jeep1970]

ok, I will check tomorrow.. whats involved with a Torque Conv leak down? just curious? Thanks!

 

[Jester32]

The fluid leaks out of the torque converter. It takes awhile to fill it up so it gives the illusion of slippage. Usually noticed when parked overnight etc . It is usually an o ring or gasket failed or spring in valve body or check ball seat worn.

 

[my98jeep1970]

ok, so I checked the fluid witht he vehicle turned off and cold.. The fluid was towards the bottom of the stock where it says to fill and right before where it says OK.. well below the full mark.. So, with that whats the next step? Thanks for your help again... will wait for your reply..

 

[Jester32]

What's the mileage have you serviced the trans recently?

 

[my98jeep1970]

Its been a while.. I did myself back in 2007. and have put an additional 20-25K on it since then... The fluid after looking at it again seems a little darker then I mentioned in my earlier reply. might have been the lighting that day.. Perhaps I should service again.. then check?... Thanks

 

[my98jeep1970]

ok, i have been meaning to report back.. I did the fluid change (NOT A FLUSH) and still have the same issue. Transmission at first start slips the first 1-2 min then runs fine the rest of the day. Also, noticed that sometimes before it slips the engine bogs down or almost dies. Again, only occurs int he first several min of operation. Next steps?? should I do I complete Flush? thinking I should of done that in the first place. Also, I was told I should of adjusted the bands? any thoughts on that? Thanks!

 

[Jester32]

Assuming the bands are adjustable they should be adjusted when serviced. It's a very critical adjustment as the shifts are timed by adjustment. To loose it can slip on a shift. To tight it can tie up.

 

[my98jeep1970]

ok, im thinking this time I will take to the shop to get a full flush. Do they also adjust the bands as part of the service?

 

[Jester32]

They should assuming they are adjustable. Some trans are some not. I would have to look up the service info.

 

[my98jeep1970]

I think they are.. My book mentioned it. I will let you know what I find out. Might just do it myself. Thanks!

 

[my98jeep1970]

ok, im back after almost a year and a half.. I garaged my jeep.. got too busy. I need to start working on it again. I was thinking of replacing some parts since I have leaks. the oil cooler lines are leaking. I will replace the oil cooler and just get a kit for the cooler lines if they make them. also, when we chatted last I think the services manual does show adjustable bands. Can you think of anything else that I should dive into? any electrical issues that might have gone out that could be causing this? Thanks

 

[digerata]

Did you resolve the shift problem? I have the *exact* same issue. Almost stalls sometimes too. Especially when going from reverse to drive.

 

[my98jeep1970]

Hello, actually I havent.. Still in my garage... I plan to start working on it this weekend. I have to change the Radiator and Trans lines since I have a bad leak, and then was thinking about adjusting the bands in the transmission.. If that doesnt fix it then I will have no choice but to take it to my local shop. What have you done so far to yours?

 

[jps4jeep]

Regarding yout oil lines, they leak probably from rust, if you intend on keeping the jeep for a long time (I generally keep my vehicles 20+ years) replace the whole line with a conversion fitting like to a -6 or -8 and then run braided stainless lines. after this replacement, I have never had a failure and generally cost s little less than the pre-bent stainless lines. For an even cheaper method, you could go with brarb fittings and press on hose, just not as pretty or trick and I am not a fan of barb fittings on a pressure line.

As for your trans issues, to be honest, sounds like it might just be time of a re-build. My thinking in the front pump is lacking fluid after rest, similar to what was dscribed above, but with out being able to drive, hard to diagnos.