One whine, two questions

[buddy]

If you look up torque converters you can purchase them for the big block chevy that shares the same one as our 6.5 diesel, and its 1300-1600. But they make them for around 2000rpm as well.

I didn't know there was a term for what I was describing, "chuggle" sounds pretty accurate. I figure with a lower stall speed I might be able to maintain lock.

 

[Dave Barbieri]

OK..........I'm still (a little) lost, say your tranny takes a dump and you need a rebuild.....What would you do as far as TC?

Louis, this is just me, speaking personally for me. I'm going to have my stock dual stator unit rebuilt by Robert and the gang at Brittain Parts Service in Houston. Leroy (PMD Cable) recommended them, and after talking to Robert I can see why Leroy is so pleased with the work they did.

What would be the overkill version?

I've looked at a lot of different websites advertising modified stall speeds, multi-disk clutches and billet construction. Prices range from $700 to $1200. For me, this is overkill. My engine will be putting out around 230hp and around 450 lb/ft of torque. I just don't need most of the high tech, high dollar stuff I see being advertised. And after AKDiesel's warning (post #4) about the multi-disk clutches, I don't really want that either.

What would be the middle ground version?

Like I said above - rebuilding my stock unit and beefing up the clutch facing material for the lock up clutch. If Robert can lower my stall speed a little - say from 2100rpm to 1800rpm, I'd be one happy puppy!

What is the OEM version?

Don't really know. I still haven't found any hard & fast data. Of course, with work going like it is, I really haven't spent much time looking. :rolleyes5: I guess true OEM would be to go back to the dealership with your TC code (tag on the converter body) and have them hand you an identical unit over the counter. Otherwise, as Buddy points out, you end up with a generic classification - B51 - which comes in three versions only: low stall single stator, high stall single stator, and high stall dual stator. well, none of that fits the shop manual description of the TC used in my 94 C3500 dually. That's why Robert will rebuild mine and hand it right back to me. I get what I want, and what I need.

And how do you know your TC is bad/going bad?.......What are the signs to look for?

Some things to look for:

• failing the stall test (post #20)
• shudder when accelerating
• weird, scary noises
• TC clutch slips under load

This is kinda general and generic. I'll be glad to post some of the specific problems from the manual if that'll help.

 

[Brooklyn Tow]

That clears it up a little.....I thought that the 4L80E was supposed to be a stout tranny to begin with, (For our application) but A fresh rebuild and a upgraded TC sounds like good peace of mind.

Just havn't heard many complaints in the tranny dept.....Something else to think about as the Dinosaurs get older.

 

[Dave Barbieri]

That clears it up a little.....I thought that the 4L80E was supposed to be a stout tranny to begin with, (For our application) but A fresh rebuild and a upgraded TC sounds like good peace of mind.

From everything I've read and heard, our 4L80E's are one of the strongest transmissions available for light duty trucks. You want something stronger, you've gotta step up to the Allison. And with that strength comes a LOT of horsepower loss due to parasitic drag. As far as I'm concerned the 4L80/85 is the best choice around.

Speaking of peach of mind - This whole project is basically massive preventive maintenance. My engine has some blow-by, but still pulls like a herd of horses. The trans has strong, solid shits and the fluid is still red. My concern is that I'm coming up on the point where mechanical things start to go sour. Since this is my daily driver, it's got to run reliably 24/7. Nest year, with fewer people doing more jobs, I won't have the luxury of spare time. Now, I have the chance to get everything together and ready to go, then do the R&R during a break or a long weekend this summer. That way, it's on my schedule. I'm trading this power train's loss of future use for peace of mind.

 

[buddy]

The trannys are strong, but it is common to have TCC solenoid and Main Pressure Solenoid wear that causes slipping or lesser TCC performance. Many may not even know if either is worn becuase it still works and they got it that way. Getting new solenoids and the sure cure kits may make a 200,000 tranny like new for $300.

 

[HighSierra86]

With all the minds on here, ive got a question that has been bugging me for a while....How exactally does a manual TC lock work?? I understand the reason in adding such a mod, but with a TC operating on all fluid, how exactly does an electronic switch come into play? Auto trannys have never been a strong point of mine, I normally leave that to the guys who do it every day. Very interesting read, thanks guys!

 

[buddy]

The electric solenoid controls fluid pressure to the converter which causes lockup.

 

[Dave Barbieri]

The electric solenoid controls fluid pressure to the converter which causes lockup.

Yup. When that solenoid opens, it allows pressurized oil to flow thru a passage that engages a clutch that mechanically locks the turbine (trans input shaft) to the pump (engine output). No more slippage, the input shaft is now locked to the engine and rotates at the same speed.