-   Full Size Jeep Forum (

AF-Jeff 09-29-2013 05:24 PM

So I was driving to autozone to get some new shocks and a new tranny mount.

But about a couple blocks away my jeep started slowing down.
I went from going 40 down to 30 and finally 20 before reaching the store.
My RPM's didn't drop. I actually had to increase the RPM's so I wouldn't drop below 20 mph.
Upon arriving my engine was hot. I barely went two miles and it was already too put my hand on the radiator cap.
I could start her easy but it was like the driveshaft was only getting a portion of what the engine was trying to put out.
also the jeep feels a little jerky and the needle was bumping all over the place.

So I need help. A lot of help. :confused:

Little Green 09-29-2013 07:00 PM

Sounds like your transmission is slipping and not allowing the power from the engine to go through to the wheels.
I believe the 727 transmission is able to be adjusted but not positive.
I think a visit to a transmission shop is in order

Renodemona 09-29-2013 07:56 PM

Could be slippage or very low fluid level. The engine was probably hot because it was running at high RPM without much cooling air being forced into the radiator. A trip to the transmission shop sounds like a near-future outing indeed. ;)

AF-Jeff 09-29-2013 09:15 PM

Well it looks like I'm going to the transmission shop. Thanks guys.

pleontks 09-30-2013 01:07 AM

79 would be the th400

Always check your fluid first whenever your tranny feels weird.

Little Green 09-30-2013 04:32 AM

Also might try trans fix fluid from Lucas. Sold at Pep Boys. Works great.

super98lsc 09-30-2013 09:51 AM

If its slipping that bad in 1st gear the clutches are likely done for. Even if the cause was low fluid by now there is probably damage done.
Tear down and inspect/replace whats bad.

Marn 09-30-2013 12:10 PM

check your fluid level in the trans, wont shift right if its too low.

If the trans is toast (TH400 is not adjustable) its only like $700-$800 to have one rebuilt, so its not the end of the world.

pleontks 09-30-2013 12:41 PM

Marn........I've been looking at tranny rebuild kits, but there's soooo many choices. What did you end up using?

Marn 09-30-2013 01:16 PM


Originally Posted by pleontks (Post 16440041)
Marn........I've been looking at tranny rebuild kits, but there's soooo many choices. What did you end up using?

I'm not a race car driver, i dont plan to enter king of the hammers, and I dont tow like it's a semi. So, the kit below was what I went with, though i did toss in an B&M plate style trans cooler.

That being said, I effed it up. Apparently one of the lip seals was not perfect, and I also slightly bent a clutch in the last pack. Took the shop 2 weeks to figure out what the heck was going on because the symptoms were so random and it air checked every time they tried. This resulted in me spending $700 to get it rebuilt after already spending $350 on a kit, a new trans case, and a torque converter.

pleontks 09-30-2013 01:53 PM

Marn.....I will be reviewing your tranny thread before tackling mine :)

Marn 09-30-2013 02:05 PM


Originally Posted by pleontks (Post 16442305)
Marn.....I will be reviewing your tranny thread before tackling mine :)

If you do it on your own, get in touch with gsmikie, or whatever. He has a DVD that is him pulling apart and reassembling a turbo400.

Thats about all I used. video quality is marginal, but it has literally every step of the process on film. My failures had nothing to do with that being my main resource, it was a lack of proper tools for the lip seals, and i am not sure how i bent the clutch. i think it wasnt seated right when i bolted down the front pump.

super98lsc 09-30-2013 02:54 PM

I have done several GM/Mopar/Ford's over the years and Marn is correct its all in the tools and attention to details. Having a good clean environment to work in, space to lay it all out on the bench then a ton of patients to check/re-check/ then check again. Items like he mentions with the lip seal tools sometimes can add up to the cost of the labor of having it built. The only "up-side" is you did it on your own an now know the unit inside and out for the "next-time".

A large cooler is the main thing for any automatic to live a long life.
If auto manufacturers installed larger coolers then autos would go 2x the distance from day one. Ask any quality shop or powertrain engineer they will say the same.
Th-400 with a solid stock rebuild will take a lot of power for a long service life, not much need to "hop one up" too much unless your stuffing a blown big block in front of it and trying to tow ships out of the mud. Just my .02


AF-Jeff 09-30-2013 08:03 PM

I topped off the transmission oil after I bought it. it was about half what it needed. I'm not sure how long it was like that. I'll check the oil lvl and get it inspected as soon as I can. I also might check the exhaust. I heard if it is blocked it could cause a reduction in speed.
I'll let you know what turns up.

jeepdaddy2000 10-02-2013 05:07 AM

Is it a Q trac? Might want to insure the t case isn't in emergency drive. Not uncommon for binding of the drivetrain to occur with the front axle engaged.

The time now is 05:40 PM.

Powered by vBulletin Version 3.8.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.