4L80 eating case bushings ?
08-26-2013, 09:39 PM
#1
On The Tree
Thread Starter
iTrader: (22)
Join Date: Apr 2004
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
4L80 eating case bushings ? Got a reasonably fresh 4L80,has eaten two rear case bushings as well as thrust washer(tried 350 pump bearing,ate it too) As a side note,first time apart(at about the 1500mile mark,when we found the initial bushing fail,with the bearing in it howling,the forward drum internal sealing surface was destroyed badly enough we had to pull/force the drum off the shaft.The 2 teflon rings were stuck in grooves,worn in the drum surface.
Replaced drum,seals,bushings and T-washer/set up endplay.worked fine.300 miles later,drop pan,brass/copper flakes/chunks in the bottom. Same damn thing,new drum shot,rear bushing shot,T-washer gunked up with material. Rear seal good,output shaft,new, 300M custom fit.Luckily no case damage,shaft still looks good.Feed tube clean/clear,rear cooler line has extension to center support,I give ! This ***** getting expensive ! Any ideas from the trans gurus ? Here is a pic of the "new" bushing,Thrust washer after 3xx miles,street driving.
Sent the forward drum out to Omega ? in Cali to install a sleeve this time in the center,hope that helps a bit. Getting tired of buying new parts every time I drive the damn thing !
Replaced drum,seals,bushings and T-washer/set up endplay.worked fine.300 miles later,drop pan,brass/copper flakes/chunks in the bottom. Same damn thing,new drum shot,rear bushing shot,T-washer gunked up with material. Rear seal good,output shaft,new, 300M custom fit.Luckily no case damage,shaft still looks good.Feed tube clean/clear,rear cooler line has extension to center support,I give ! This ***** getting expensive ! Any ideas from the trans gurus ? Here is a pic of the "new" bushing,Thrust washer after 3xx miles,street driving.
Sent the forward drum out to Omega ? in Cali to install a sleeve this time in the center,hope that helps a bit. Getting tired of buying new parts every time I drive the damn thing !
08-26-2013, 09:54 PM
#2
Did you cut and clean the converter and flush the cooler/lines between failures?
Was the trans COMPLETELY disassembled and all parts cleaned?
If not, do it the correct way and start over.
I wouldn't sleeve a forward drum. Just replace it. One more failure point and the area that wears on a forward drum isn't really a spot I would sleeve. It's not a smooth bore, it has a channel cut in it for oil flow.
Everybody thinks it's a simple cut and dry operation to rebuild a transmission. We spend 1.5-2 days per unit doing them and still have some take up a huge amount of time on the dyno to dial in the pressure or have to be torn back down. I dyno'd a 4L80E today with an odd clicking noise that has no visible cause on teardown.
Was the trans COMPLETELY disassembled and all parts cleaned?
If not, do it the correct way and start over.
I wouldn't sleeve a forward drum. Just replace it. One more failure point and the area that wears on a forward drum isn't really a spot I would sleeve. It's not a smooth bore, it has a channel cut in it for oil flow.
Everybody thinks it's a simple cut and dry operation to rebuild a transmission. We spend 1.5-2 days per unit doing them and still have some take up a huge amount of time on the dyno to dial in the pressure or have to be torn back down. I dyno'd a 4L80E today with an odd clicking noise that has no visible cause on teardown.
08-26-2013, 10:17 PM
#3
On The Tree
Thread Starter
iTrader: (22)
Join Date: Apr 2004
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
Converter was replaced during first teardown.Trans completely disassembled,clutch packs checked,VB cleaned,cooler-lines blown/flushed. Same problem(or headed that way again) I am not too inclined to buy another drum as I feel like the seal surface is a weak point and have to think that at least trying a steel sleeve may help to prolong or protect said surface.But what do I know,NOT a trans guru ! I appreciate the input,I really think this is lack of lube or perhaps a plugged feed hole to the rear bushing ? I also noticed earlier( I think) output shafts are drilled in the rear bushing area for oil feed but later ones(mine included) are not.I can send the converter back to Coan again,****,may as well order a spare trans,the whole 4L80 thing is a waste of time for me.Should have put a 400 in it and been done,this things more fragile than a 60,doesnt run long enough to break anything. BTW,this trans was NOT built by Jake,or any other vendor here,dont misunderstand my frustration ! I appreciate Jakes help and input,Rossler came through as well for me and is going to take a look at the valve body/seperator plate and trans brake setup as well.
08-26-2013, 10:32 PM
#4
If it's not built correctly, it's not going to live. I assure you, it's not more "fragile" than a 4L60E.
Mechanical components must be lubricated with clean oil. If there is a blockage in the lube system or contamination, parts WILL fail, no matter what kind of unobtainium they are made of.
There is nothing wrong with the stock forward drum. You can make a steel sleeve if you wish but watch the oil flow. You could cut off the flow to the forward clutches.
What year core is this and what are you using for a rear cooler fitting?
Mechanical components must be lubricated with clean oil. If there is a blockage in the lube system or contamination, parts WILL fail, no matter what kind of unobtainium they are made of.
There is nothing wrong with the stock forward drum. You can make a steel sleeve if you wish but watch the oil flow. You could cut off the flow to the forward clutches.
What year core is this and what are you using for a rear cooler fitting?
08-26-2013, 11:41 PM
#5
On The Tree
Thread Starter
iTrader: (22)
Join Date: Apr 2004
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
97 core case,-6 AN fitting with proper length ext tube attached to feed center support(verified with a stock gm quick connect) No other apparent damage to trans,all shifts good EXCEPT reverse slight delay( maybe because of transbrake ?)
08-27-2013, 12:15 AM
#7
On The Tree
Thread Starter
iTrader: (22)
Join Date: Apr 2004
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
Mismatched rear planets restricting lube flow ? If I lay out the parts and take a pic can you tell if something is wrong/mismatched ? Hell,I will be happy to pay some shop time ! R&R and teardown plus drums/bushings,and full synthetic fluid is killing me !
Trending Topics
08-27-2013, 12:30 AM
#8
Yes,
mismatched rear geartrain components will foul up your day, and it's easy to do if you have different year model stuff laying around.
Post up pics of the rear of the center support. The drive tube, the intermediate shaft, the rear ring gear and bearing, output shaft, and sun gear.
mismatched rear geartrain components will foul up your day, and it's easy to do if you have different year model stuff laying around.
Post up pics of the rear of the center support. The drive tube, the intermediate shaft, the rear ring gear and bearing, output shaft, and sun gear.
08-27-2013, 02:02 PM
#9
On The Tree
Thread Starter
iTrader: (22)
Join Date: Apr 2004
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
Here are the parts in question.Builder says all appear late model stuff,I dont know how to tell.
VB is late model,short feed tube to rear,tube is clear,both directions.One possibility(maybe? ) Transbrake does NOT work,possible wrong separator plate causing lack of lubrication,or blocking a needed passageway ? I will ask Karl to look at that for me,maybe thats the issue ?
VB is late model,short feed tube to rear,tube is clear,both directions.One possibility(maybe? ) Transbrake does NOT work,possible wrong separator plate causing lack of lubrication,or blocking a needed passageway ? I will ask Karl to look at that for me,maybe thats the issue ?
