4L80E overrun clutch damage question
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Teching In
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4L80E overrun clutch damage question Hi
I'm tearing down a 4L80 to rebuild. It's out of my 97 K3500 with 120k miles. I'm converting the truck to right hand drive to drive here in Australia. While the body is off I figured why not rebuild the trans? The transmission is very clean, everything looks pretty new. Thrust washers, frictions, filter, fluid, bushings all look decent. Not much on the magnet. I wonder if it hasn't been rebuilt before. The truck was very well looked after before I imported it. The trans did leak pretty bad through the fittings, shaft and wiring harness though. It drove fine.
The only damage I've found so far is the overrun clutch frictions and hub. Obviously I'm replacing the frictions, but my question is do I need to replace the hub as well? And has anyone seen this before? I've attached some pictures.
Thanks in advance.
edit: I should say the overdrive clutch friction plates and the overrun hub. These are the larger overdrive frictions that are damaged.
I'm tearing down a 4L80 to rebuild. It's out of my 97 K3500 with 120k miles. I'm converting the truck to right hand drive to drive here in Australia. While the body is off I figured why not rebuild the trans? The transmission is very clean, everything looks pretty new. Thrust washers, frictions, filter, fluid, bushings all look decent. Not much on the magnet. I wonder if it hasn't been rebuilt before. The truck was very well looked after before I imported it. The trans did leak pretty bad through the fittings, shaft and wiring harness though. It drove fine.
The only damage I've found so far is the overrun clutch frictions and hub. Obviously I'm replacing the frictions, but my question is do I need to replace the hub as well? And has anyone seen this before? I've attached some pictures.
Thanks in advance.
edit: I should say the overdrive clutch friction plates and the overrun hub. These are the larger overdrive frictions that are damaged.
Last edited by Miles B; Feb 27, 2016 at 04:59 AM.
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
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From: Fort Worth, Texas
Check where the Input Shaft engages the Forward Drum for damage, If no damage is found replace the forward drum bushing & both Stator bushing anyway along with all 4 sealing rings on the input shaft.
It's hard to see bushing wear sometimes, Check the Sun Gear Shaft bushings by placing it on the Intermediate shaft & check for wobble, Usually the front bushing is worn more.
It's hard to see bushing wear sometimes, Check the Sun Gear Shaft bushings by placing it on the Intermediate shaft & check for wobble, Usually the front bushing is worn more.
On The Tree
Joined: May 2013
Posts: 189
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From: Newman Lake, WA
Also, make sure you replace the large sun gear shaft bushing in the center support. This is arguably the most important bushing in the transmission. Wear here (which, as clinebarger said, is often difficult to detect) will allow the sun gear shaft to wobble, which will allow the direct drum, which is splined to the front of this shaft, to contact the center support. At this point, it's game over for both pieces... Just press it out of there and put a new one in. It's cheap... Make sure that you line up the lube hole in the bushing with the passage in the center support.
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Teching In
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Oh I'm replacing all bushings, seals, frictions, steels, pistons, solenoids etc. For an extra couple hundred bucks it's cheap peace of mind. Pulling a 4L80e off the back of a 454 with a transfer case and front differential to contend with is not fun. Best to do it now while the body is off.
I'll dress the scratches on the hub teeth with a fine stone and see if the frictions move smoothly. I haven't figured out which thrust washers to order yet either.
I'll dress the scratches on the hub teeth with a fine stone and see if the frictions move smoothly. I haven't figured out which thrust washers to order yet either.
