Transmission not holding 3rd & 4th
Thread Starter
Teching In
Joined: Jul 2011
Posts: 8
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From: Oregon
Transmission not holding 3rd & 4th I just lost 3rd and 4th gear in my transmission, it will shift into but not hold when I give throttle. I have a 1998 Pontiac Trans Am with the 4 speed automatic 4L60E GU5 for the LS1. Does anyone know the best solution for this or know of anyone parting out their A4 LS1 Firebird/Trans Am/Camaro with the GU5 Transmission? Any help is greatly appreciated, thank you.
Last edited by PONTIAC MUSCLE; Apr 27, 2014 at 03:44 PM.
Moderator
Joined: Aug 2010
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From: Ann Arbor, MI
You already asked this question in this thread:
https://ls1tech.com/forums/automatic...-4th-gear.html
I answered it there:
Nope different problem; your 3/4 clutch is worn out, the most common problem reported here.
You either need a rebuild or a replacement trans. You don't need a specific "GU5" (whatever that is), any '98 to '06 300mm input shaft 4L60E or 4L65E will work perfectly.
https://ls1tech.com/forums/automatic...-4th-gear.html
I answered it there:
Nope different problem; your 3/4 clutch is worn out, the most common problem reported here.
You either need a rebuild or a replacement trans. You don't need a specific "GU5" (whatever that is), any '98 to '06 300mm input shaft 4L60E or 4L65E will work perfectly.
Teching In
Joined: Apr 2014
Posts: 1
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From: Iowa
4L60 junk Im new here, but pretty sure GU5 is a GM rear axle option code.. and good luck with a 4spd auto. Ive had many, they all turned into junk with very few miles and no fluid loss or provocation. Spent thousands on rebuilds from different builders, and few miles later junk junk junk. Waste of time or I have terrible luck. Wish all GM vehicle were T56 or muncies..
Thread Starter
Teching In
Joined: Jul 2011
Posts: 8
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From: Oregon
Thanks, it did'nt notify me of your reply. GU5 is 3.23:1 gears and GU2 is 2.73:1. I hate autos but I got a very good deal on the car. mrvedit thank you brother, i'm still learning how to use this thread thing.
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Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Also I don't think the Vortec 5000 is a LS engine and therefore will not have the correct input shaft. Changing the output or input shaft requires a complete rebuild.
If you want to PM me links to CL, that will be fine; I get email notifications of PMs and therefore will respond quickly.
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They make stage 1/2/3 kits for rebuild - I bought a stage 2. Transco shift kit, high performance boost valve (sonnax), corvette servo, 11 plate ( 3-4 clutch pak ), clutches Kevlar, hi energy band (2-4 band) beast shell, etc.