Problem with 4L60

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workingdog

GOLD Star
Joined
Sep 17, 2006
Threads
489
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3,109
Location
Santa Rosa, CA
2 1/2 years ago I had a 5.3l/4l60 installed in my '84 FJ60. The 5.3 has a Magnusen glower installed on it, but because I've never been able to get all the gremlins out of the system, I've always been very timid with the gas peddle.

Last summer, towing a 2,400 pound tent trailer from Santa Rosa to Lake Tahoe and back, we lost second gear completely. The band was gone. The original installer recommended a transmission guy in Sunnyvale. I had the transmission removed, sent it to the guy in Sunnyvale - who did the job on the side as a 'favor' to the installer which turned out to be a real PITA. After $3,000 plus dollars - mostly to have the tranny removed and reinstalled. I was back in action.

Then over labor day, towing a 1,600 pound side by side in a utility trailer up to Lake Tahoe I lost third gear. I assume the band is gone again. RPMs went through the roof as the truck slowed and we coasted back to Auburn Friday night of Labor Day weekend with only second gear.

I've put 15,000 total miles on the conversion and I keep the boost below 0 almost all the time only occasionally hitting 1 or 2 psi. I did have a cooling gremlin which was allowing the engine to overheat - we think we finally nailed it down to a leaking coolant bottle cap at pressure. So, although it will now hit 217-220 on a climb, the fan kicks in and it cools off - eventually.

This is the FJ60 I inquired about the value of recently. It is has been so reliable that I can't trust it trips with my boys. It has left me stranded on the side of the road too many times in the last couple of months. I was going to take a bath on selling it and just move on, but now that its sitting in Jack in the Box parking lot in Auburn with a blown transmission, I have to figure out what to do.

I am very relucttant to spend another $3,000 fixing the transmission again. I have neither the facilities at my house or the experience to do it. Plus, I think there is problem with the the way the 5.3l/4L60 was installed. This isn't a 700R4 which completely stands alone. The TCM is quite involved.

Here's what I have noticed over the last 2 years - but I have no idea if it is related to this failure or not.

When on a long, sustained climb, like climbing up to Donner Summit, about half way up, it will stay in 3rd gear. Donner summit is a 5,000 ft climb in a series of steps, and when it starts to do this it won't shift into fourth even on the short down hill breaks between steps. Now, I'm saying it's won't go into 4th, but I really don't know as I can't tell whether the TC is locked or unlocked. The transmission is so smooth it's very hard to tell. Eventually, it seems like it recovers from whatever is bothering it and shifts into 4th for the last quarter of the climb. I have no transmission temp gauge on it. I should - but I don't. I have OBD II gauges, but transmission information isn't available.

I was looking at getting a better programming tool that would allow me to monitor the transmission, but it's too late for that now.

The original installers answer is that these issues and transmission failures are totally unrelated to the installation and to each other - they are just transmission problems and he is refusing to help.

Since the last transmission was repaired 'on the side' - I have to recourse with that shop. Besides, getting the car/transmission back and forth to Sunnyvale is a real pain in the ass.

What do I do?
1. Sell the car as it sits, take a huge bath on the thing, and chalk it up to my own stupidity?
2. Invest in putting a new 4L60 in it at a cost of at least $5,000 and risk it all happening again.
3. Invest in putting a NV4500 behind it.

Any input would be appreciated, other than pointless flaming or trolling.

Peter
 
2 1/2 years ago I had a 5.3l/4l60 installed in my '84 FJ60. The 5.3 has a Magnusen glower installed on it, but because I've never been able to get all the gremlins out of the system, I've always been very timid with the gas peddle.

Last summer, towing a 2,400 pound tent trailer from Santa Rosa to Lake Tahoe and back, we lost second gear completely. The band was gone. The original installer recommended a transmission guy in Sunnyvale. I had the transmission removed, sent it to the guy in Sunnyvale - who did the job on the side as a 'favor' to the installer which turned out to be a real PITA. After $3,000 plus dollars - mostly to have the tranny removed and reinstalled. I was back in action.

Then over labor day, towing a 1,600 pound side by side in a utility trailer up to Lake Tahoe I lost third gear. I assume the band is gone again. RPMs went through the roof as the truck slowed and we coasted back to Auburn Friday night of Labor Day weekend with only second gear.

I've put 15,000 total miles on the conversion and I keep the boost below 0 almost all the time only occasionally hitting 1 or 2 psi. I did have a cooling gremlin which was allowing the engine to overheat - we think we finally nailed it down to a leaking coolant bottle cap at pressure. So, although it will now hit 217-220 on a climb, the fan kicks in and it cools off - eventually.

This is the FJ60 I inquired about the value of recently. It is has been so reliable that I can't trust it trips with my boys. It has left me stranded on the side of the road too many times in the last couple of months. I was going to take a bath on selling it and just move on, but now that its sitting in Jack in the Box parking lot in Auburn with a blown transmission, I have to figure out what to do.

I am very relucttant to spend another $3,000 fixing the transmission again. I have neither the facilities at my house or the experience to do it. Plus, I think there is problem with the the way the 5.3l/4L60 was installed. This isn't a 700R4 which completely stands alone. The TCM is quite involved.

Here's what I have noticed over the last 2 years - but I have no idea if it is related to this failure or not.

When on a long, sustained climb, like climbing up to Donner Summit, about half way up, it will stay in 3rd gear. Donner summit is a 5,000 ft climb in a series of steps, and when it starts to do this it won't shift into fourth even on the short down hill breaks between steps. Now, I'm saying it's won't go into 4th, but I really don't know as I can't tell whether the TC is locked or unlocked. The transmission is so smooth it's very hard to tell. Eventually, it seems like it recovers from whatever is bothering it and shifts into 4th for the last quarter of the climb. I have no transmission temp gauge on it. I should - but I don't. I have OBD II gauges, but transmission information isn't available.

I was looking at getting a better programming tool that would allow me to monitor the transmission, but it's too late for that now.

The original installers answer is that these issues and transmission failures are totally unrelated to the installation and to each other - they are just transmission problems and he is refusing to help.

Since the last transmission was repaired 'on the side' - I have to recourse with that shop. Besides, getting the car/transmission back and forth to Sunnyvale is a real pain in the ass.

What do I do?
1. Sell the car as it sits, take a huge bath on the thing, and chalk it up to my own stupidity?
2. Invest in putting a new 4L60 in it at a cost of at least $5,000 and risk it all happening again.
3. Invest in putting a NV4500 behind it.

Any input would be appreciated, other than pointless flaming or trolling.

Peter

Spend 400$ get a used 4l60e cut the output or swap out the one from your other transmission. Then get a good reader on the Trans and see what the heck is happening. Seriously don't spend 5k. A good used unit will be fine to diagnose the problem and honestly they will run 200k anyway. Once you get it sorted have it rebuilt with a reputable builder or just run it for 50k then do it.
 
there should have been a custom tune put on the pcm for the blower and the trans settings should have been changed too. Do you know who did the pcm tuning? I have been running these trans for a long time and never had the bands just let go. you should be putting down about 375hp to the wheels with a 112 maggie. you can get a fully built trans that can stand 700hp for $2000 or so but if the computer isn't tuned right it can die real quick.
 
Take the blower off the 60...go back to normal setup.... Find a 2500 or other type pickup to tow with. I don't recall but I don't remember anyone with a long term proven V8 swap with supercharger on a 60.
I know the idea of removing the blower is most likely not very tolerable and certainly cost $$$.. Find another 5.3 and sell the supercharged 5.3.

What does Magnusen say in regard to PCM modifications required or hard modification required of a 4l60E to stand behind a supercharged 5.3? You don't have any problems with trans cooling or trans temps? Seems like you would get some slippage or other warnings before you just drop a gear in the auto transmission.

I would think cooling the entire setup is questionable on a FJ60 platform with a v8 and supercharger. I'm sure you've seen the threads regarding V8 swap cooling. Towing with a supercharger on a V8 FJ60...would seem to push the cooling question to mission impossible.

I don't have any magic answers, but I know torque and heat kill auto transmissions. If it was shifting fine and not hunting for a gear or lag between shifts then one might think the programming is good and its only a trans issue. On step climbs it would be normal to come out of high gear and potentially stay in the next lower gear depending on load...of course if towing...it would be desirable not to climb steep climbs in OD.

You may have some electrical gremlins in the PCM programming and or if that engine requires a separate transmission controller (I don't know). I do know that "they" can program the PCM to not show certain check engine codes and or to simply turn off the warning. So you can't depend on the programming if you know nothing about who did it or what they did. I don't think its too painful to come up with another PCM and have it programmed but you are still down with a auto trans that has broken twice... finding the real answers may be too costly in $$ and time.

IF you like the truck I would $hit-can the supercharger in whatever manner works...and run a conventional fuel injected 5.3 (which a number of guys have done without major issue). OR I think you would be forced to carry the truck to one of the hot-rod shops that has a long history with fuel injection and that specific engine-supercharger-transmission....and lay out some big $$ for advice or suggested modifications, I expect cooling is not going to be solved but that's just my view. The towing part adds complexity to the issue...at least to the cooling and load on the components and places to look for failure points.
 
Damn that sucks... I had a t-case blow up on mine.

Keep the truck, do what they ^ say. Its all part of the fun eh'

Cheers
 
Thanks for the thoughts.

I don't have the facilities or the skills to swap in a used 4L60.

Magnusen did the PCM reprogramming and have asked them what they did and have gotten no response.

I agree with mwalls54 that it seems like the reprogramming isn't right and that is contributing to these early failures. The 4L60 should be able to handle what I've got. This set could be in a Surburan towing a lot more than 2,400 pounds.

One of my problems is that the installer bought the supercharger, handled the reprogramming through Magnusen (I think it had to be sent back and done again) and I no visibility into what was done or any ability to call the manufacturer and get more information.

I'm looking for a recommendation for a tool that would allow me to monitor the transmission. I haven't been able to identify one. It's not throwing any codes, which is really surprising.

All I need to do to get rid of the blower is get a 5.3 intake and reprogram the PCM back to stock.

But, I'd really liked to understand what's going on before I spend all that money.

Peter
 
One more question:

Where do I go to learn about TCM programming and what might be wrong with mine that is causing these early transmission failures. I've been unable to find anything on the web. You can find all you want about engine tuning, but the transmission is a black hole.
 
there is no real tcm for the 5.3 4l60e its a pcm all in one. I frequently tow trailers with my 60 and have weighted out at the dump dropping off over 5000lbs not including the dump trailer. going up a steep grade with this kind of weight the trans will drop down to 3rd gear and stay there even if you let off the petal until it reaches a point where it senses a lesser load. some times it stays in 3rd longer than I think is should but my understanding is that its more efficient to stay in 3rd for a short distance than it would be to shift to 4th and than back to 3rd when you start slowing down and pushing on the petal harder. I think you just got a lemon of a trans, maybe one that wasn't assembled properly, or its getting too hot. I run 2 trans coolers when put them next to each other they equal about the size of my radiator in surface area.
 
Thanks for the reply.

Yes, I understand the TCM is incorporated into the PCM on GM trucks. Where do I find out the elements of that part of the PCM that controls the transmission? Overheat mode? TC lock and unlock? How load is used to alter shift points?

I haven't been able to track it down and none of the people I can find that are transmission 'experts' actually not anything about the electronic part of the transmission.They all still seem to live in a 700R4 world.

Peter
 
My question is

When you have the 4L60 rebuilt, did the rebuilder rebuild your transmission or did they rebuild another one and use yours as a core for another transmission?

If they rebuilt your transmission, my thinking is that possible the housing itself is warped, putting something out of spec and causing the failure.

Anyhow, that's my WAG.

Apart from that, can you get a stand alone TCM?
 
One more question:

Where do I go to learn about TCM programming and what might be wrong with mine that is causing these early transmission failures. I've been unable to find anything on the web. You can find all you want about engine tuning, but the transmission is a black hole.

there are ls engine based forums that have lots of information on it. I know of a few shops in the chatsworth area that are very experienced in the ls motors and trans. Tuning software like efi live(what i use) and hp tuners are how you check your trans and engine settings.
 
They rebuilt the same transmission. If I continue with the 4L60, I definitely won't use the same core again.

I don't really need this truck to have an automatic. How tough is it to convert to manual (clutch pedal, et al)? I've got to take the entire thing out, why not just put an NV4500 in and loose what ever the problem is in the process?

Peter
 
I don't really need this truck to have an automatic. How tough is it to convert to manual (clutch pedal, et al)? I've got to take the entire thing out, why not just put an NV4500 in and loose what ever the problem is in the process?

Peter

There have been a couple of people in the hardcore corner who put an NV4500 behind the 5.3 and 6.0 and that opens up a new can of worms. Since the 5.3 and 6.0 never came with a manual transmission, the PCM needs to be reflashed etc. Not that it isn't doable, its just different.
 
They rebuilt the same transmission. If I continue with the 4L60, I definitely won't use the same core again.

I don't really need this truck to have an automatic. How tough is it to convert to manual (clutch pedal, et al)? I've got to take the entire thing out, why not just put an NV4500 in and loose what ever the problem is in the process?

Peter

Because on top of what you mentioned you will need a new adapter, a new pcm tune and possible new exhaust depending on how it was run. Nothing wrong with that but you will pretty much be paying to redo 2/3 of an engine swap since you mentioned you do not have the room or time to do this yourself. It shouldn't cost you 5k to get a new transmission in there.

For 2k you can get a level 4 or 5 4l65e which will handle 500-700hp depending on which version you go with. With that said even the stock 4l60e should have handled what you have for much longer than 15k with an easy foot. Something has to be not locking up or shifting correctly. Who knows maybe it was a poor rebuild as well.
 
Wow - that 5.3 never came with a manual? That means it's not a CARB legal combination in Calif.

So I have to stick with the 4L60. I need an expert to reflash the PCM that knows superchargers.

I guess I need to find a local hot rod shop that knows that kind of stuff. I have a few places I can look.

PEter
 
"Shifting so smooth" bothers me somewhat. In truck applications, the 4L60Es generally shift a little bit on the firm side. If it is shifting super smooth, it was likely not rebuilt properly, or the blower tune is not commanding enough line pressure.
 
^^^ This.
I had my 4L60E go out when I did my frame swap.
No particular reason... I lost 3 and 4th gear
I remember it shifting so smooth that I would know it shifted ONLY cause of the muffler sound.

After the rebuild at $1800 the shifting was/ is very crisp... I can feel the shifts as they happen....
Any reputable tranny shop should be able to do this job and provide you with a few years warranty..
They also put in writing the componens they use brand and part number...
The shop I used gave me a 3 year warranty provided that I bring it in every 15k for an oil change.
 
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BTW I use a scan gauge II to monitor my water and tranny temps through the PCM.....
 
Manuchao and LeadHead. Thanks for the useful information. I am very suspicious of the PCM programming for the blower.

I have two ODB II gauges and can't get either to show me tranny temps - you are?

I know I can find a local, reputable shop to put a new tranny, but finding someone that ensure the PCM is programmed right is going to be tougher.

Peter
 
You'll be throwing your $$ away if you do not address the PCM first.
My scan gauge II shows the tranny temps.. there was some info I needed to input (cant remember), but the new ones read the tranny temps right off the bat..
I would contact this guy Brenna guy at http://www.lt1swap.com/programming.htm
for programming.
He might steer you in the right direction, and his prices are not bad at all.....

Good luck..
 

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