Clunk wasn't rear end It's 48RE

[teamfish]

Took My truck in to the dealer to find out what the clunk was when it shifted into low gear, called them yesterday afternoon the dealer was consulting with DC on the problem. Seems in the early 90's (46RE) there was a problem with the overdrive when it would kick out 18mph or so it would thump. They claim that this is unheard of with 48RE but they need to take out my over drive unit to try to tighten it up. Anyone else had this? I'll find out more on Monday when they take it apart.

 

[rbattelle]

Yikes! Usually a clunk means a bad u-joint. Hope they know what they're doing...

Ryan

 

[DrDiesel]

Took My truck in to the dealer to find out what the clunk was when it shifted into low gear, called them yesterday afternoon the dealer was consulting with DC on the problem. Seems in the early 90's (46RE) there was a problem with the overdrive when it would kick out 18mph or so it would thump. They claim that this is unheard of with 48RE but they need to take out my over drive unit to try to tighten it up. Anyone else had this? I'll find out more on Monday when they take it apart.

Sorry to tell you this, but taking out your overdrive unit to tighten it up is a lack of techno speak for the inability to know whats wrong. :{

So they tell you some vague load to put you off until they sort out what it is. :-{}

The overdrive is not something you can removed and tighten up... What a load of Crap. :{

I would be willing to bet they have misinformed and misdiagnosed your truck. Now your posting a bad rap on the 48RE without proper verification.

 

[tgrfan2]

Sounds like the same tech that told me I was blowing the hose to the intercooler off on my 2000 due to a dirty air filter!

 

[Alan Reagan]

I can tell you what it was when my 05 was doing it. The transmission was missing a thrust washer from the factory causing the thunk sound when it down shifted. The dealer found it without removing the transmission. They put one in and it fixed the problem.

 

[Floor It]

The overdrive can be tightened up but I'm not sure that really is the problem. Thats wild that DC left out a thrust washer.



John

 

[teamfish]

I was told that if I was to drive it with the OD cut out it would not be doing what it is doing. I know when I drive in tow haul it does it at a hight speed. I'll know more on Monday I want to be a believer (48RE) just glad I didn't have my exhuast brake in yet no excuses if you know what I mean.

 

[DrDiesel]

The overdrive can be tightened up but I'm not sure that really is the problem. Thats wild that DC left out a thrust washer.



John

Are you confused between the TCC and some other component.

The overdrive as it is being called in this thread is a clutch inside the T/C

that is operated by fluid pressure as set by a regulator.

Can you explain how you can tighten this... ... .

 

[robmints]

I think under the overdrive piston has a shim. I think they might be talking about the overdrive unit on the back of the transmission. It looks like you could get it off without dropping the transmission. But I only saw it done on a video and it was already out. And I have no idea if it would make a clunk. For all I know it might make it sprout wings.

 

[Floor It]

Are you confused between the TCC and some other component.

The overdrive as it is being called in this thread is a clutch inside the T/C

that is operated by fluid pressure as set by a regulator.

Can you explain how you can tighten this... ... .

No, they said that they were taking the overdrive unit out, the back half of the transmission which is the overdrive unit. The Torque Convertor Clutch is a different componet which has nothing to do with overdrive.



John

 

[teamfish]

Alan Reagan You are the winner they took my transmission apart today called me and told me it was missing apart. I asked is it was a thrust washer? All he could do was ask me how I knew. I should have my truck back tomorrow YEA!

Thanks Knute

 

[JValdez]

Does anyone know what the long term effects are if a truck is driven without this thrust washer?

 

[teamfish]

Good Question I plan on asking what kind of wear and tear my truck endured, it only has 7000 miles

 

[AWestbrook]

Awesome thread guys. THis is the way things are supposed to work here.

 

[rbattelle]

Does anyone know what the long term effects are if a truck is driven without this thrust washer?

Whatever lies behind the thrust washer would have handled the loading. Instead of smooth contact between the two parts via the washer, there would be direct contact, resulting in abrasion of one or both parts.

Besides that, every component along the shaft (probably the output shaft) was probably axially mis-located an amount equal to the thickness of the thrust washer.

It's hard to do anything but speculate without knowing exactly which thrust washer was missing.

Ryan

 

[cerberusiam]

Does anyone know what the long term effects are if a truck is driven without this thrust washer?

If its the one I am thinking of the wear is happening on the drive shell and the case. More so on the case I would guess. Either way, the long term effects are NOT good.

 

[JValdez]

I will be doing a transmission service shortly on my truck. Would there be any evidence in the pan of the washer being missing. Maybe extra shavings or something? Would they be aluminum type shavings or steel shavings?

My truck has this type of "clunk" but it's not bad and I always assumed it was the rearend making this noise. Like I said it's only a slight clunk but i've noticed it.

 

[teamfish]

I should be picking my truck up today. The Dealer called at 4:30 yesterday and said that the parts got in late and it should be ready sometime today. I have a lot of questions for them, Most of all, What kind of problems if any are to come. And what did they have to do to fix it. I'll let you know.

 

[robmints]

If you go to hemitruckclub.com and download the service manual you will be able to at least see some of the parts and have an idea of how they go together. The 48re OD is at about 21-1380 or about page 7900 in adobe.

 

[JValdez]

teamfish,

Let us know what they tell you. I may have to make a trip to the dealer and have them take a look.