What causes A4's to break?
Tech Resident
Joined: Jan 2006
Posts: 5,117
Likes: 3
From: Philly
Originally Posted by RICEETER
so, i've read this whole thread and all i keep seeing is "the stock tranny fries because of power and rpm's". what about the heavily built trannies, such as performabuilt and rossler? can they be spun to 6800 and last? or are they not worth 3k? my car is a 410-420 rwhp forged 347 with a 150-200 shot.
so to answer your question, can performabuilt or rossler build a 4L60E to hold 600rwhp? of course, definitely. will the 4L60E last for years being taken to the track every week and having the **** beat out of it? i can't answer that, but i'd personally doubt it. ANY tranny will eventually fry, no matter what. the key is to maintain it (fresh fluids and filters and regular inspection in a race car). a 4L60E is a very capable transmission - but only if built properly.
I am still taking my time and decided to work on the tranny a little tonight. I think that I have found another weak link.
I was planning on ordering a new sprag, but this just confirmed that I have to....
I was planning on ordering a new sprag, but this just confirmed that I have to....
Actually there used to be something better made by raybestos called the mechanical diode .unfortunatly is is no longer available
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Originally Posted by performabuilt
Actually there used to be something better made by raybestos called the mechanical diode .unfortunatly is is no longer available
Well I thought it worked rather well but then it dosnt matter because its not made anymore
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It was a piece of 
. The shop I was working for thought they we good as well. This changed after we broke quite a few in my buddies car along with about a dozen customer cars. I learned that a new product needs to be tested in house in different applications before it is sold to the public. Come backs are not cheap and pissed of customers even worst. Vince
. The shop I was working for thought they we good as well. This changed after we broke quite a few in my buddies car along with about a dozen customer cars. I learned that a new product needs to be tested in house in different applications before it is sold to the public. Come backs are not cheap and pissed of customers even worst. Vince well maybe I was lucky didn't have any problems with them but only got to us a few then they were gone , though the patent did transfer to ford and they began using the design in the 4r70w for the intermediate sprag and still do
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Funny that you mention the use of it in a Ford. They also tried to use this in the 4R100/E4OD and ATSG says to use the earlier style sprag type one way clutch. In the 4R110W they are having all kinds of problems with them as well. In the AODE/AOD they used a spring and roller style intermediate one way clutch. This would fail when the springs became weak or developed flat spots on the rollers and the races. This is why Ford did what they did. Although Gm used this same technology at first in the 400 and found that a sprag type one way clutch worked much better. Kinda like what alot of guys use in the TH350 for the intermediate one way clutch. They remove the spring and roller setup and replace it with a sprag type one way clutch. The 4R70w is the only unit that I have ever seen the diode work in but have also seen it fail in high RPM applications. I believe there are guy's out there converting those drums to sprag types as well. Well enough of the history lesson. Vince
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Verdad Gallardo Yes i have seen it lock both ways myself , but I have also seen it replace cronically breaking roller types in the AOD and AODE to and take a massive pounding .
We last year had a mustang gt 91 that had a aod and 273 gears it hit very hard and had been built by a couple shops one had already ungraded it to the aode roller sprag and wider aode band but the sprag on it to had exploded twice , We tried the 4r70w diode sprag and its been a year and so far so good , But time will tell but the customer is happy he actually got one to hold up more than a couple months , I have heard stories from both sides of the isle but My own experience has been good so far but them i have only used that type sprag a few times as we dont do alot of fords and the sprag for the 700R4 4L60E wasnt around long so only used a couple of them but never heard of any problems from one customer , And at least one of them I know is ok its in my brothers truck fo years now of course its used for heavy towing and not so much hipo but it gets abused pulling a large camper and boat regularly so who can tell , But Since its no longer available its really now a mute point on wether its any good .
But thanks for the input I like information .
We last year had a mustang gt 91 that had a aod and 273 gears it hit very hard and had been built by a couple shops one had already ungraded it to the aode roller sprag and wider aode band but the sprag on it to had exploded twice , We tried the 4r70w diode sprag and its been a year and so far so good , But time will tell but the customer is happy he actually got one to hold up more than a couple months , I have heard stories from both sides of the isle but My own experience has been good so far but them i have only used that type sprag a few times as we dont do alot of fords and the sprag for the 700R4 4L60E wasnt around long so only used a couple of them but never heard of any problems from one customer , And at least one of them I know is ok its in my brothers truck fo years now of course its used for heavy towing and not so much hipo but it gets abused pulling a large camper and boat regularly so who can tell , But Since its no longer available its really now a mute point on wether its any good .
But thanks for the input I like information .
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Originally Posted by Vince @ FLT
That's the 1 I use. Did you get it complete with the races?
Joined: Nov 2001
Posts: 34,629
Likes: 2,550
From: Schiller Park, ILL Member: #317
The #1 reason why A4 transmissions break is due to driving the car. If you never use the car, the trans will last simply forever.
Nothing leads to more breakage than driving the car. Period. NO debate, NO arguement. This is 100% FACT.
Nothing leads to more breakage than driving the car. Period. NO debate, NO arguement. This is 100% FACT.
Now That Is a fool proof statement HA ha
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Originally Posted by 02 BLK WS6
I don't think that it came with races... Do you carry races???? Where can I get races??? Not sure if it was a good deal, but I paid $47 shipped for it. The current ones looked smooth at first glance, but what should they mic out at??
FormerVendor
Joined: Oct 2006
Posts: 3,123
Likes: 3
From: D-F/W
When inspecting the races all you really have to know is that the bearing / roller contact area is hardened just like a wheel bearing race. Ordinarilly that makes for stronger but more brittle steel. The races associated with a failed sprag are ordinarilly chipped, dented, cracked, pitted, discolored or otherwise very obviously hammered. If they look anything other than spotless and shiny do not use them.
If either the inner or the outer bearing / roller surface areas are damaged then it is recommended that both be replaced. A new GM or aftermarket assembly is available for around $150.00 - $175.00. I do not have a problem installing used components here... either they are not good parts or they are good parts. Obviously there are other wear considerations to be made but my point is don't be afraid to install used components using sound judgement as to their viability. Oh... and common sense goes a long ways when dealing with hard parts. You'll do fine.
Hope that helps.
g
If either the inner or the outer bearing / roller surface areas are damaged then it is recommended that both be replaced. A new GM or aftermarket assembly is available for around $150.00 - $175.00. I do not have a problem installing used components here... either they are not good parts or they are good parts. Obviously there are other wear considerations to be made but my point is don't be afraid to install used components using sound judgement as to their viability. Oh... and common sense goes a long ways when dealing with hard parts. You'll do fine.
Hope that helps.
g
