Why All the Tranny Hate?

[Fleeingpepper]

Everyone on here says how the transmissions aren't very high quality and go bad a lot. But why exactly is that?
Do they fail often on the ones made prior to 1996? My dad has a truck with 265,000 miles on it with no tranny rebuilds and it shifts perfectly.
The 4L60-E is only rated to handle 360 ft-lb of torque. And the vortec 5.7 is rated at 330 ft-lb, and I have heard that they were underrated. So the transmissions are handling at almost their peak torque allowance. GM should've put beefier transmissions in these things.
The 4L60-E is a good transmission, it's just being pushed to its limit.

 

[brielly]

From what i understand the sun shell used in these trannies had some quality issues. Some are ok and some were flawed ans caused the tranny to fail early. If you get a good one the tranny should last a long time provided its well maintained and not beat on.

 

[NYrr496]

I had one wear out at 135,000 miles. No towing or anything. Then that rebuild failed because of a corroded connection at the computer didn't increase the line pressure for 3-4 gear. My last trans failed with the exact same symptoms, but we couldn't pinpoint a problem. Thankfully, my trans guy warranteed it, I changed the computer and installed a guage to monitor line pressure. So far, no more problems.
If you ask me, they fail suddenly with little or no warning.

 

[JDWX]

Lotsa hate, but considering how many are out there and do well, it's a wash.

I used to think how crappy caravan trans must be as I always had one to four in my shop that were fried. But, when you figure there were hundreds of thousands of them running around, they're probably not so bad really.

 

[95TwinTT]

The 4L60-E is only rated to handle 360 ft-lb of torque. And the vortec 5.7 is rated at 330 ft-lb, and I have heard that they were underrated. So the transmissions are handling at almost their peak torque allowance. GM should've put beefier transmissions in these things.
The 4L60-E is a good transmission, it's just being pushed to its limit.

I agree that the 4L60e is a good tranny, but GM should have been using the 4L80e in all of the trucks. The 3/4 clutch pack in the 60's are just not enough.

The 4L60e can be built to take up to 600 hp, but it cost a lot to do it right.

I also think a lot of guys get into trouble when they start adding things to the engine to make more power. They can forget about the trans in the excitment of making more power.

Adjustments to the trans should be made along with adding power in front of it. Just my .02...........

 

[79powerwagon]

95Twin is onto the real reason- people don't take care of their stuff, and don't understnd how it works, so they have failures. Instead of blaming their own ignorance, they blame the manufacturer, true to the American spirit.

The number one cause of transmission failure is HEAT, second to DIRT. When the owners manual says to flush the tranny at whatever intreval it says, DO IT! Install a new filter, too! If you tow (or soup-up your engines output), install a BIGGER cooler. A tranny fluid temp gauge is a good idea too!

Slapping a "cold air intake and some 22"S" doesn't a hot rodder make. LEARN and UNDERSTAND your systems, and you'll be way ahead!

 

[Biggwaukegan]

is it hard to swap to the 4l80e? what about a bigger tranny pan to get more fluid pushin threw?

 

[Beef]

Agree with who ever stated to use the 4L80

Just had my 60 rebuilt using all upgraded and hard parts.
heavy duty GM clutch kit,
heavy duty GM 2-4 band
GM overhaul kit with filter
heavy duty reaction carrier,
number 2, udpgrade to the corvette style servo and
3 update the Bosch type pressure control solonoid and
install a heavy duty .500 boost valve.
heavy duty sprag and reverse drum

But here is why my trans failed, Email from my trans guy.....

"Got the trans. out and apart. The band did fail, but it failed because the input sprag locked up. What the sprag does it has 2 splined gear faces on it that hold different clutches. When you are in first gear it hold against the other side to give you the power to take off. In 2nd it doesn't really do anything and the same for 3rd. but in 4th gear the lower gear will over run the upper to allow the overdrive. What happend was it couldn't over run because it was locked up that made the reverse drum keep spinning which burnt out the band. Also the reverse drum is trashed because once the band wore down the rivets in the band chewed it up. Just think of a brake shoe once it is worn down and chews up a brake drum. Same thing here, just on the opposite sides. Anyway we will need a heavy duty sprag and reverse drum so......."

 

[John Redcorn]

So what's everyone's opinion on changing the fluid and filter on a high-mileage trans that it's unknown if it's been done before? I know a lot of people say don't touch it and I'm kind of starting to be on their side as of a year ago.

I bought my tahoe with 135k miles. should I do it or not?

Also, can I tell if it's been replaced? is the vin # supposed to be on it anywhere?

I changed my trans fluid and filter every 30-40k in my grand prix that I bought new, everything was perfect then my 4th or 5th time doing it winter 2007 at around 140k with the same brand fluid and filter, all kinds of problems started right then. I mean like on the first drive after I was done. hard shifts, delayed shifts kinda "hunting" for the correct gear, did that for almost a year, then in november 2008 it quit going into 4th or locking up. still does 1-3 with hard shifting and no lockup though. (I would've put the old fluid back in to see what happened but I drained it into a pan full of leaves and cigarette butts )

 

[Beef]

Have you tried to take your car somewhere to get fully flushed??

 

[treepete]

man, I havent done ANY trans maintenance on the D, and now Im scared to do any if I have a chance of fouling it up... Maybe a trans filter and a visit to the t-tec machine is in my future. or maybe a whole new tranny...

 

[Untitled415]

A lot of times a flush will actually mess up the trans more at higher milage because of the fact of puttin new fluid in will actaully increase the hydralic pressure more. It does this bcause the old fluid breaks down over time at the same rate as all the seals in the trans so when u put new fluid in the trans the new fluid isnt broken down like the old fluid and will put more pressure on the old seals which often can cause problems!!

 

[Fleeingpepper]

I've always wondered why putting new fluid in can screw it up.
Thanks!

 

[John Redcorn]

I've also heard old fluid carries with it in a suspension particles of worn clutch packs and other junk that helps everything work right and when you put new atf in, since the clutch packs and other magical transmission stuff are missing the material and now the fluid is too, problems!

 

[treepete]

man.,.. is 135K too late, or "high mileage"?

if it is, im going to back to driving like a girl.. see how long I can stretch it out.

 

[79powerwagon]

Hey guys? Check your fluid levels and set them correct. If the oil is vaguely red in color and doesn't smell like smoke (still smells like oil), you should be just fine. Change the fluid and filter and be done with it.

It the fluid doesn't pass one of those two tests, start looking for a core to rebuild...

 

[Untitled415]

The method of rule we use at the shop is if its not broken dont fix it. But if you are having problems liek slippin or what not and are goin to need a rebuild it wouldnt hurt to try new fluid and see if it helps the problem, the worst that could happen is you would still new a rebuild....

Hmm nothin against 79powerwagon but i kinda dissagree. First off always over fill the trans at least half a quart to a quart... and like stated above i wouldnt start messing with it if its not broken especially over 100000. If hte fluid looks good just check the level and add what needs to be added. Nothin against powerwagon just my opinion...

 

[Shane87]

is it hard to swap to the 4l80e? what about a bigger tranny pan to get more fluid pushin threw?

I am curios on weather or not anyone has ever swapped in a 4l80e because I plan on using my Tahoe to tow my jeep to and from off road park

 

[clkelley]

I have to say something about servicing the trans with higher mileage or not. The issue with a lot of people getting them flushed isn't the difference between the new and old fluid, etc. It has more to do with the process by which you flush. Most lube places and a lot of dealerships use flushing machines to replace the fluid, which isn't always a bad thing if done right. The issues arise when you have a shop that does the flush with a machine while also using chemical dispersant. The chemical dispersant breaks down the built up material on the clutch packs causing the old fluid's additives, etc to be removed unevenly and at times in chunks. This material then floats through the valve body and filter, at times clogging the filter and causing flow issues and sometimes clogging the valve body disrupting flow. I have actually known of shops "Jerry-rigging" their machine lines to fit when they don;t have the right fittings to perform the flush, I have heard of shops using machines with inadequate capacity for the tranny being flushed, etc. Then you have to hope that the person performing the flush is not only properly trained to do so but that he is having a good day, etc. there are so many factors there it is amazing.

Another factor after a flush is the fact that with ANY full flush of the tranny where you replace the filter and properly flush the fluid, there should be a "Break-in" period where you take it easy on the tranny to give the new fluid time to kind of settle in, settle down, etc. Allowing the new fluid time for it's additive package to go to work is essential.

All that being said, there is an extremely simple procedure known as the "Hoot Flush" method that just about anyone with a few simple tools and a buddy to help when needed can perform. I have done it many times and never had an issue that wasn't already suspected. (I had on Tahoe that was already suspected for the tranny slipping and they wanted me to flush it, well, within about three weeks, out of nowhere it just quit shifting from 3-4 so the customer just opted to replace it with a new one with a warranty.)

We also must take into account one last factor. When you read so much information online about transmission or other problems, it is those people who are having problems that are getting online looking for help. You rarely EVER hear from people without problems because it is just not on their mind and I would bet that they outnumber those with problems by a substantial amount. If this wasn't the case GM wouldn't really be able to get away with continuing to install the 4L60E in their trucks.