Sound of DEATH (Transmission)

[swathdiver]

Sucks to hear this. I think the rebuild price is high. I have a thread started asking for recommendations for upgraded transmissions, since mine is on the way too. I was looking at these: https://cahallperformancetrans.com

I’m looking at the performance trans and I think it’s very reasonable @ $1200+ core, etc.. also would need a torque converter.
Most of the responses in my thread were referencing upgrading to a different model transmission, like a 6L80E, which would be great, but I don’t think I’ll be spending that much to convert it. It would also need a separate computer I believe, and more into it than I want to think about. Another option I’m looking into is a 4L70E conversion, which I believe should be almost plug n play. If so that’s a no brainer, as it’s rated quite a bit higher HP / TQ numbers from the factory.

ETA: Just spoke with Cahall and they informed me they would be able to match the strength of the 4L70E into my 4L60E, so no real conversion necessary, just stronger components to get it there. I do not believe this would include the 5 pinion planetaries, so not sure if that would be worth upgrading to the 4L70 or not. More research to do. Also a couple billet parts are recommended, since our trucks weigh so much, so that bumps the cost up. So far though I’m pretty happy with what I’m hearing. I’ve got to figure a rough estimate for my HP when it’s all done, to have an idea what to plan for. May end up with the pro-race, rather than the performance transmission. Significant cost difference.

ETA2: from the Cahall site:

*Any vehicle using any power adder, is over 400 RWHP, is over 4000 LBS, or is using drag radials or slicks MUST be equipped with the additional billet steel output shaft @ $450 and billet input reaction shaft @ $300

I did a little more reading too. The 4L70 has different internals and is more efficient but you can upgrade your 4L60 to a 4L65 with the 5 planetaries and be plenty strong for what you want to do.

John, what did you decide to do?

 

[Sam Harris]

I did a little more reading too. The 4L70 has different internals and is more efficient but you can upgrade your 4L60 to a 4L65 with the 5 planetaries and be plenty strong for what you want to do.

John, what did you decide to do?

Thanks for your help! It’s going to be more than I expected at first, but I always figure- if it breaks, upgrade it! Now I just need to save some money for this beauty to get her new crankshaft to driveshaft converter doohickey.

 

[rockola1971]

The vids sound like the input sunshell broke the weld where the shaft meets the shell. Makes all gears neutral. For those that dont know, the shaft that you mate to your torque converter when installing is the sunshells input shaft. The sunshell receives all the torque from the engine first before it ultimately gets passed on to the the output shaft of the tranny. Busted sunshell is quite common on vehicles used for towing and back up alot and dog legging during the back up doesnt help. Thats when they usually fail.

 

[Michigan]

I did a little more reading too. The 4L70 has different internals and is more efficient but you can upgrade your 4L60 to a 4L65 with the 5 planetaries and be plenty strong for what you want to do.

John, what did you decide to do?

I called a couple shops this morning and weighed my options. I could of had a used trans put in for about 1,200 but didn’t want to go that route. Never know how the trans was taken care of out of a junkyard.

Shopped around and most shops quoted 1,600-2,500 for rebuild depending on “hard part damage” with a 1 year warranty

I called the called the shop that it’s at and asked if he can give me a solid number even before getting into the trans and he said if there’s any hard part damage he’ll charge me cost price on those parts and he said he’ll keep it under 2,000 with a 2 year warranty

So they are going to start in the rebuild tomorrow. Said it should be done by Friday

I asked about a bigger trans cooler. I don’t know much about it but he said he can put one before the radiator and connect it. Is a bigger trans cooler necessary for regular every day driving


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[Michigan]

The vids sound like the input sunshell broke the weld where the shaft meets the shell. Makes all gears neutral. For those that dont know, the shaft that you mate to your torque converter when installing is the sunshells input shaft. The sunshell receives all the torque from the engine first before it ultimately gets passed on to the the output shaft of the tranny. Busted sunshell is quite common on vehicles used for towing and back up alot and dog legging during the back up doesnt help. Thats when they usually fail.

Excuse my lack of knowledge would this mean it needs a complete rebuild? Lol


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[NoReverseYukon]

Excuse my lack of knowledge would this mean it needs a complete rebuild? Lol


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If it is just the sunshell that broke, you dodged a bullet. Easy and not-too-expensive repair.
Usually the sunshell just strips out and you lose reverse and 2nd. If it broke, it probably looks like this...

 

[Michigan]

If it is just the sunshell that broke, you dodged a bullet. Easy and not-too-expensive repair.
Usually the sunshell just strips out and you lose reverse and 2nd. If it broke, it probably looks like this...
View attachment 238499

I may never know because even if it is just the sunshell that broke their going to charge me for the whole rebuild unless their going to be honest


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[Sam Harris]

I called a couple shops this morning and weighed my options. I could of had a used trans put in for about 1,200 but didn’t want to go that route. Never know how the trans was taken care of out of a junkyard.

Shopped around and most shops quoted 1,600-2,500 for rebuild depending on “hard part damage” with a 1 year warranty

I called the called the shop that it’s at and asked if he can give me a solid number even before getting into the trans and he said if there’s any hard part damage he’ll charge me cost price on those parts and he said he’ll keep it under 2,000 with a 2 year warranty

So they are going to start in the rebuild tomorrow. Said it should be done by Friday

I asked about a bigger trans cooler. I don’t know much about it but he said he can put one before the radiator and connect it. Is a bigger trans cooler necessary for regular every day driving


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Go with the trans cooler. Trucool 40k. And get the one with the cold weather bypass if you live in a cold climate: LPD4739 model. Keeping the transmission cool is probably the #1 thing you can do to prevent wear / breakage. LPD47391 is the same one for our trucks without the cold weather bypass valve.

 

[OR VietVet]

I may never know because even if it is just the sunshell that broke their going to charge me for the whole rebuild unless their going to be honest


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I ran shops but no trans specialty shop. If I had a trans out and found this sunshell broke I would also have to assume that some metal went thru this transmission. I would insist on a full rebuild as they have promised and the 2 year warranty. If the customer just wants to replace one part I would sign off on it but allow no warranty. Guess who would be on the hook if something else goes bad in there 3 months later. The shop. Warranties I gave were for maintenance and repairs. I never gave a warranty for patch work. There could be problems with the previous rebuild that you said you thought was 3 years ago.

 

[Michigan]

Go with the trans cooler. Trucool 40k. And get the one with the cold weather bypass if you live in a cold climate: LPD4739 model. Keeping the transmission cool is probably the #1 thing you can do to prevent wear / breakage. LPD47391 is the same one for our trucks without the cold weather bypass valve.

Thanks for the part numbers. Our winters do get cold in Michigan.

I do not do any towing or off roading in this truck. I drive it 30 miles to work each way, mainly freeway. Do you guys think a trans cooler is necessary?


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