Engine/Transmission (1994 - 1998) 47RH problems

[ndurbin]

The other day while I was cruising down the highway the transmission kicked outta OD. I hit the OD button on the dash and it went right back in. Well when I get to the next town and am getting back upto speed leaving the town right after the TC locked up it slipped alil bit (not much but enough to get my attention). Well I watched alil more carefully the next time it was locking up. It seems to slip under medium/heavy acceleration but doesn't slip under light acceleration. And then yesterday and today driving around town the shifts are real soft mushy and right before each shift it seems to slip/hesitate to shift. TC lockup now is really soft too.



It's a Blumenthal HD transmission with their triple lock convertor and it's only got about 10,000 miles on it. So it's atleast still under warranty. TPS snesor and trans temp sensor are both less than 6 months old. And I have the TPS wires in their own loom.



The transmission was doing fine up until it just decided to kick outta OD but since then it has gone to crap. I thought I'd see if anybody had any ideas before I drive the 2 hours back to where I had it installed to have them look at it.



TIA

Nathan

 

[Joe G.]

It sounds like low line pressure to me. That usually indicates a lot of wear. Since it's still under warrantee you should take it back to them.

 

[JGheen]

Yeah, I would just take it back to the guy who built it for you if it is still under warranty. With the warranty all you'll pay is the fuel out to the shop and back, right?

Unless getting the time to go have it checked out is a factor like any kind of truck time is for me.....

 

[ndurbin]

I just didn't want to drive 2 hours up there and 2 hours back for it to be some little thing I could fix myself.

 

[ndurbin]

Well I went out and drove it alil more yesterday and this morning. The truck is real sluggish, I hoped in this morning fired it up and put it R and the truck didn't move. It finally started to creep backwards after about 15 seconds. Then for about the first 5-10 min out driving around it was real sluggish taking off from a stop. Then I noticed when it shifted it couldn't make up its mind between which gear it wanted to be in. It'd go back and forth b/w 2nd/3rd 3 or 4 times before it decided on being in 3rd. It did the same thing between 3rd/4th. The TC lockup is still the same, anything over half throttle when it locks up makes it slip. Also it will unlock if I try to speed up to pass someone. The RPMs well go up to about 2600-2700 before it locks back up.



I called and talked to the place I had put it in and they seem to think that the kickdown cable is out of adjustment. But would that cause the TC to slip?



TIA

Nathan

 

[SEmerson]

It could do some of the symptoms but not all. Plus there is now damage from the slipping.

 

[Joe G.]

I doubt very much that the kickdown cable could cause those symptoms. Real low ATF could do that. I suspect that all the slipping has thrashed the trans.

 

[ndurbin]

Well I found the problem, theres a pretty good sized hole in one of the transmission cooler lines where it goes over the front crossmember. I hadn't noticed any leaks since I park on grass mosta the time, I saw the puddle when I went over to a friends house. When I got back home I pulled the dipstick it was super low on fluid.



Thanks

Nathan

 

[fortunate1]

Low ATF level

That's a bummer. I hope that you didn't drive much with the level too low. When I bypassed the coolant/ATF cooler a few years ago, I had a scare similar to yours. The hose that was re-routing the ATF past that cooler was attached pretty well... or so I thought. Turns out that I should have pushed it onto the steel lines a little more & used 2 hose clamps instead of just 1 at each end. I hit the highway for a 3 hr trip, and about 45 min into it the trans seemed to slip & the rpm went up.



2 things saved my trans from being trashed that day: a Mag Hytec DD pan that held enough ATF to allow for the leak (more like a sliced jugular vein) and I shifted into N & pulled over to shut down IMMEDIATEDLY. I ran that trans for another 60K - 70K miles before rebuilding with a master upgrade kit.



Bottom line: your trans may still live to see another day IF you didn't drive too much/hard before discovering the leak.

 

[ndurbin]

No I didn't drive to far. My friend's house was only about 2 blocks away and it had been sitting there idling in N for about 10 min before I noticed it. I shut it down soon as I spotted it. Then once I got home I put some Penzoil ATF+3 (b/c of the lack of something better at hand). I filled it back up and test drove it pretty easy and everything seemed to work OK. I should have a new line tomorrow or Wed. and I plan on changing the filter and getting rid of the Penzoil with fresh fluid (it's about due for a change anyway).



Nathan

 

[ndurbin]

Well I finally got the lines and everything in last friday and got around to getting the new lines put in today. Went for a little test drive and I think all my good luck charms failed me. TC seems to still be slipping and it's still kinda sluggish when I take off from a stop.



I think I am just going to park this POS till I have the time and money to tear the whole frickin truck apart and fix everything right instead of half @$$ mechanic's working on it anymore.



Anybody know of a GOOD cheap 12 valve/ 5spd. looking for a new home?



Nathan

 

[Joe G.]

If you have a service manual and are pretty good with tools you can overhaul it. The clutchs are probably burned up. That results in low pressure as well as a lot of slipping. TST products sells a heavy duty overhaul kit.

 

[ndurbin]

I looked around TST's website and I couldn't find anything about a HD transmission kit. The only things they had under automatic trannies was ATS stuff (TC, VB, and rebuilt transmission).



Nathan

 

[Joe G.]

It is mentioned in the last paragraph on this page: http://www.tstproducts.com/tranny_kits_trial.htm



I don't see it on their price list so I guess you will have to call them and find out what is going on.