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What is applied when a 4L60 is in reverse

7K views 21 replies 5 participants last post by  Billvill 
#1 ·
Just like it says above I am looking to find out what components are applied in reverse. My 4L60 developed a delay and now a shutter in reverse.

I may decide to build it before I destroy it.
 
#3 · (Edited)
I haven't built a box in 25 years. ( I was a Mopar line mechanic at a dealership years ago ) I see there are a ton of parts out there for the 4L60. I have a deep pan and a cooler. I was thinking about the corvette servo. The 9 plate 3/4 pack and the line pressure increase orifice. Last but not least the S10 converter which should give me just a little more stall speed.

Its not a race car but it does have a very healthy 350 in it. I do tow a small trailer with it. maybe 2000 lbs tops. I do like to do a burn out with it once a year at our van club truck in.

Is there anything else I should beef up for a solid rebuild. Should I go for the wide bands and drums along with the good spraug. Where do you draw the line ?


One thing that strikes me odd is that low gear aka manual 1 is solid as a rock. Could the one way clutch be an issue. I wasn't leaning that way because a very slight delay started about 2 months ago. I have to assume it is a hydraulic issue.

Thanks billy
 
#5 ·
another thing that it could be that we just found for the same problem is the reverse boost valve, just had the exact same thing, reverse drum and the low/reverse clutches air checked just fine, but i still heard a shuttering noise, through the pump, found out it was the reverse boost valve, and replaced it. (whole pump, didnt have a reamer for the fix that sonnax has. just another idea
 
#6 ·
One thing that strikes me odd is that low gear aka manual 1 is solid as a rock. Could the one way clutch be an issue. I wasn't leaning that way because a very slight delay started about 2 months ago. I have to assume it is a hydraulic issue.
My 4L60 developed a delay and now a shutter in reverse.
two different things happening here.

You have a shutter in "R"....... Good holding in "manual 1"

as posted in shifter position "R" the reverse input clutch and the L/R clutch are holding. The "sprag " is NOT holding in "R".... as the sprag does "hold" in "manual 1". The sprag does NOT hold in "R" , so it is not a factor.

You can perform this test: ( as briscoe points out the 'year' of this box can determine how it reacts)

Drive the vehicle to max speed 25 mph.... move the shifter quickly to "manual 1 " as you lift off the gas pedal... Does "manual 1 " quickly take hold and provide engine braking?? IF it delays or seems a bit lazy , you may have a L-R clutch problem. SInce you have a mild shutter problem , this test may show limited results to work with


NEXT:

Last but not least the S10 converter which should give me just a little more stall speed.
The S-10 converter for the small V-6 (2.8 liter)engine uses a different input shaft / Spline count setup.

IMHO..... You will not be happy with a S-10 converter behind a V-8 engine.
 
#7 · (Edited)
Its a 93 4L60E If I accelerate enough backing up my driveway where the rpm comes up raising line pressure I can nail it and there is no shudder. Leads me to think it is a hydraulic issue. I will do the manual shift down test tomorrow. I ran it on a 600 mile trip last week. Before I did . I did a filter and a deep pan. It has about 130K on it and had nothing real ugly in the pan. I had a "corvette servo" on the shelf for about a year and installed it also. That was a waste of my time in that the servo in the box was exactly the same size.

My son in law was backing it up the other day with a trailer on it to move a few things around. He isn't aware there is a problem ( he never drives my van ) anyway he hit it hard in reverse and it spun the tires. Go figure.

I have a core coming and I am going to build one. I would appreciate imput about what goodies to install.

ps: that 600 mile trip was my first highway run with 3.73 gears in the van. That gear and the box in OD is an absolute perfect cruiser @ 70 mph.
 
#10 ·
what is applied

Bill this unit has an aluminum piston in the reverse input drum. Once you have it apart, look at that piston carefully. You will see a bleed hole in the piston, where the bottom 'waved' steel plate will flatten out against the piston, when this piston is applied.

Close that hole down in size. When new, this hole may not be a consideration, but, after awhile this hole size, because of many reasons, will let too much reverse oil leak thru, creating a reverse delay, or shudder in reverse.

I would suggest a transgo shift kit, a better sun gear shell, maybe the beast sun shell, a kit that provides the ability to install more clutchs in the 3-4 clutch pack.

There seems to be no end [ relative to parts ] to what you can install into the 4L60e trans, as you strive to make it better. Good luck!
 
#11 ·
Thats exactly what I have come to believe. I am leaning toward stepping up to the 4L80. I was talking to Dave Jarvis who drag races a full size chevy van. The truck leaves wheel up and is close to breaking into the 9's with a small block. I asked him what box he was using. He told me it was a bone stock 4L80 with a good converter. If a clean low mile unit becomes available I think i will go that way. If I build a bullet proof 4L60 I could have over $800.00 in parts in it.

Thanks for the input.
 
#12 · (Edited)
Billvill said:
Thats exactly what I have come to believe. I am leaning toward stepping up to the 4L80. I was talking to Dave Jarvis who drag races a full size chevy van. The truck leaves wheel up and is close to breaking into the 9's with a small block. I asked him what box he was using. He told me it was a bone stock 4L80 with a good converter. If a clean low mile unit becomes available I think i will go that way. If I build a bullet proof 4L60 I could have over $800.00 in parts in it.

Thanks for the input.

budget in some extra cash for the conversion to a 4L80E unit....

drive shaft mods , fresh slip yoke, crossmember mods, wire harness conversion , ECM re-programing....

i may have forgotten something

:cool:
 
#13 ·
I have heard about the bleed hole from another builder also. He suggested opening up the separator plate to increase oil flow when reverse is applied. I wanted to install a shift kit no matter what I do so i think I may take that suggestion.

Any Input ? Do you guys know if the Transgo kit maps out the reverse flow hole in the separator plate ?
 
#15 ·
I think I am going to give that option a play. The trans just shifts and operates flawlessly in all forward gears. I really don't want to R&I it at this time. If the larger boost valve and opened up fluid feed does not resolve my issue I haven't spent any extra in that I would have added those items to the overhaul list.
 
#17 ·
Actually I found a 95 4L60E on our local craigslist with a converter and aluminum drive shaft out of a pickup for $150. He claims its good with high mileage. I may buy it just for a core to build. I have a 4L80 shaft with the good 1350 ujoints that I scored but the two yokes for the 4L60 and 10 bolt will cost me $100. I am hoping the pick up truck drive shaft is the same length as my van.

I do see where the 93/94 separator plate is one part # from Transgo and the 95 is a different #. Does anybody know if the 95 model is better or worse?
 
#18 ·
Billvill said:
Actually I found a 95 4L60E on our local craigslist with a converter and aluminum drive shaft out of a pickup for $150. He claims its good with high mileage. I may buy it just for a core to build. I have a 4L80 shaft with the good 1350 ujoints that I scored but the two yokes for the 4L60 and 10 bolt will cost me $100. I am hoping the pick up truck drive shaft is the same length as my van.

I do see where the 93/94 separator plate is one part # from Transgo and the 95 is a different #. Does anybody know if the 95 model is better or worse?

the separator plates are different because the lock-up strategy was changed to PWM in 1995.
 
#19 ·
I feel like a rookie here PWM ?

Is that torque management ? If it is could I use the 93 valve body in the 95 unit ? I have heard nothing but bad things about torque management. I do have to do a burnout once a year at our clubs truck in.

PS: If my van didn't look and run so good, I would buy something from this century. However I don't think they build em like they used to.
 
#20 ·
4l60e

No they don't build them like they used to, they build them better.

Many shops in my area have been slow this summer, I think they build them better now.

PWM is an acronym for pulse width modulation. Instead of an on off solenoid application, PWM allows for a partial application of components, such as torque converter clutchs. Maybe a, too simplistic explanation.

Your computer may not like the 95 valve body.

But I'm not too bg on switching stuff around anyway.

You don't want to stick with what you have? You said it drove and upshifted good, just a shudder in reverse, correct?
 
#21 ·
torque management is the system that cuts power of the engine and pressure inside the trans during a high torque load upshift,

I have scanned a few vehicle systems with software from EASE diagnostic using a laptop computer. i did this during various levels of torque load on the vehicle.

The PCM will cut the engine timing advance back to zero at a high load upshift ( WOT). I saw this on a 2000 Silverado 5.3 2wd truck (mine).

I'll add to briscoe comments.... with the PWM systems of lockup there are new materials on the converter clutch to with stand the slippage of the lockup clutch.


:cool:
 
#22 ·
ok I got it. Fluid is directed just like fuel thru an injector via PWM what will they thing of next.

I do want to keep my trans. I a paraplegic and use a wheel chair. I have hand controls and a lift in the van. I am interested in the 95 box for a usable unit while I build mine. I don't want any downtime.

I am a big believer of repairing what you have. That way you always know what you have.
 
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