Which auto transmission do I have?
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Joined: Dec 2005
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From: Horn Lake, MS
Which auto transmission do I have?
What model do I have?
I'm thinking it is an A518, and if I understand correctly, that is just a 727 with overdrive. But, I'm not sure. Can somebody fill me in on this? I'm adjusting my bands, and the book has different specs for different models.
Thanks
I'm thinking it is an A518, and if I understand correctly, that is just a 727 with overdrive. But, I'm not sure. Can somebody fill me in on this? I'm adjusting my bands, and the book has different specs for different models.
Thanks
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Joined: May 2005
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From: Belvidere, NJ
You are correct, it is an A518, similar to the 727 with some minor changes to accomidate overdrive.
727's are used in 89-91 non-intercooled 3-speed auto
A518's are in 91-93 intercooled trucks, 4-speed OD auto
47RH's are in 94-95 trucks, 4-speed OD auto w/ lockup torque converter.
727's are used in 89-91 non-intercooled 3-speed auto
A518's are in 91-93 intercooled trucks, 4-speed OD auto
47RH's are in 94-95 trucks, 4-speed OD auto w/ lockup torque converter.
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From: socal
apperently the 47rh is the auto to have because of its lock up capabilities. not sure if anything else about it is better. to be put in a 1st gen truck it requires a shortened drive shaft and repositioning of the cross member, i believe? someone who knows better should chime in...
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From: Belvidere, NJ
Mine has a 47RH, the only trouble is with a lockup converter is that you can actually put enough power through it to burn it up.
I didn't touch my drive shafts. I did have to lengthen the slots in the plate that bolts onto the crossmember. Had to hack and chop the the four wheel drive lever bracket to get that to clear the reenforcements around the rear servo and bend the handle slightly.
I didn't touch my drive shafts. I did have to lengthen the slots in the plate that bolts onto the crossmember. Had to hack and chop the the four wheel drive lever bracket to get that to clear the reenforcements around the rear servo and bend the handle slightly.
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You can add lockup to any 518, for that matter 727s. Use L/U input shaft, reaction shaft support and valve body, and of course a quality converter. The only difference between the L/U and non L/U reaction shaft support is the addition of a circuit block ball staked into a hole in the support. I would go with 48re I/P shaft and support, they have improvements and are stronger. To do pre 90 727s requires using older L/U shaft and support, or using later outpu shaft, the newer inputs do not have the large bushed hole in the end for the pilot on the output shaft. Also the 727s never had the hole in the case for the L/U-O/D electrical connector, I know of 2 different ways guys got around that problem.
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From: Boerne, TX
Originally Posted by txs
You can add lockup to any 518, for that matter 727s. Use L/U input shaft, reaction shaft support and valve body, and of course a quality converter. The only difference between the L/U and non L/U reaction shaft support is the addition of a circuit block ball staked into a hole in the support. I would go with 48re I/P shaft and support, they have improvements and are stronger. To do pre 90 727s requires using older L/U shaft and support, or using later outpu shaft, the newer inputs do not have the large bushed hole in the end for the pilot on the output shaft. Also the 727s never had the hole in the case for the L/U-O/D electrical connector, I know of 2 different ways guys got around that problem.
THANKS!! 
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I will do some checking but I think on the 518s a guy could get by with the non L/U valvebody, just change the bar on the side of the valvebody that has the O/D selenoid to the one with 2 selenoids, L/U and O/D. There are 3 screws that hold it to the body.
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