possible broken pump 4L60E?
Thread Starter
Staging Lane
Joined: Jan 2014
Posts: 61
Likes: 2
possible broken pump 4L60E? So been working on my friend 68 firebird. Got the LS1 conversion up and running.
The tranny fluid level won't go down. The trans is a rebuilt that he got from the a auto salvage company that they installed tranny to the vette engine.
I think they didn't install the torque converter correctly and broke the pump so the trans isn't circulating fluid. Added 8 quarts and nothing. Any thoughts would be very helpful. Thanks
The tranny fluid level won't go down. The trans is a rebuilt that he got from the a auto salvage company that they installed tranny to the vette engine.
I think they didn't install the torque converter correctly and broke the pump so the trans isn't circulating fluid. Added 8 quarts and nothing. Any thoughts would be very helpful. Thanks
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
First lets be sure you have the right trans; I assume we are talking about a 4L60E.
Q1 - Does it have a removable bell housing?
Q2 - Does it have a bolt hole at the top of the bell housing in the 12 O'Clock position?
If No to either Q, you need to adapt the old-style trans to the LS1.
If Yes to both Q, it does sound like the converter is not engaged into the pump rotor, and/or the pump is broken.
Q1 - Does it have a removable bell housing?
Q2 - Does it have a bolt hole at the top of the bell housing in the 12 O'Clock position?
If No to either Q, you need to adapt the old-style trans to the LS1.
If Yes to both Q, it does sound like the converter is not engaged into the pump rotor, and/or the pump is broken.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
There are 298mm and 300mm input shaft versions of the 4L60E. See my post #2 in these threads:
https://ls1tech.com/forums/automatic...s1-4l60-e.html
https://ls1tech.com/forums/automatic...uld-i-buy.html
The LSx engine will only directly bolt up to a 300mm input shaft 4L60E, which are only '98 and later for V8 (LSx) engines.
The C5 Corvette with LS1 engine used the 298mm input shaft, but there is a long torque tube between the engine and trans, i.e. the trans did not bolt directly to the engine.
If the trans really is a '97 then it is almost certainly a 298mm version.
A 298mm 4L60E (or 700r4, 200r4, TH350, TH400) will bolt up to an LS2 engine if you bolt a pilot hole spacer to the end of the flexplate. The reason is that the LS engine's crank is shorter than a SBC/BBC and the converter will otherwise not seat into the crank. The LS converter's mounting holes radius is a bit different from 298mm and older converters. However the difference is small and the LS flexplate holes can be elongated by 1/8" to make it work. Do this when you have the converter and flexplate on your work bench.
Assuming your trans converter are currently bolted up, then you either have a 300mm trans, the mods above were already done, or they forgot the spacer (which will soon cause vibration).
I suspect that a 298mm trans/converter bolted to a LSx engine without the spacer would work Ok until it started to vibrate.
In other words, my questions about which version of the trans you have don't actually explain why you have no fluid pressure, but just trying to ensure everything is build correctly.
Of course the first step is to check that the converter bolts are installed.
https://ls1tech.com/forums/automatic...s1-4l60-e.html
https://ls1tech.com/forums/automatic...uld-i-buy.html
The LSx engine will only directly bolt up to a 300mm input shaft 4L60E, which are only '98 and later for V8 (LSx) engines.
The C5 Corvette with LS1 engine used the 298mm input shaft, but there is a long torque tube between the engine and trans, i.e. the trans did not bolt directly to the engine.
If the trans really is a '97 then it is almost certainly a 298mm version.
A 298mm 4L60E (or 700r4, 200r4, TH350, TH400) will bolt up to an LS2 engine if you bolt a pilot hole spacer to the end of the flexplate. The reason is that the LS engine's crank is shorter than a SBC/BBC and the converter will otherwise not seat into the crank. The LS converter's mounting holes radius is a bit different from 298mm and older converters. However the difference is small and the LS flexplate holes can be elongated by 1/8" to make it work. Do this when you have the converter and flexplate on your work bench.
Assuming your trans converter are currently bolted up, then you either have a 300mm trans, the mods above were already done, or they forgot the spacer (which will soon cause vibration).
I suspect that a 298mm trans/converter bolted to a LSx engine without the spacer would work Ok until it started to vibrate.
In other words, my questions about which version of the trans you have don't actually explain why you have no fluid pressure, but just trying to ensure everything is build correctly.
Of course the first step is to check that the converter bolts are installed.
