AW4 teardown video
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: Transmission & Drivetrain
Forum Description: If it's between the engine and wheels, it goes here
URL: https://theamcforum.com/forum/forum_posts.asp?TID=119135
Printed Date: Apr/18/2024 at 6:31pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: AW4 teardown video
Posted By: amcguru
Subject: AW4 teardown video
Date Posted: Mar/25/2023 at 2:03pm
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To avoid any confusion, this is the Toyota version of our AW4, and for all practical purposes are mechanically identical. https://www.youtube.com/embed/pSTeisqdiQY" rel="nofollow - https://www.youtube.com/embed/pSTeisqdiQY ------------- 
NAMDRA #3646 "I believe the best social program is a job" ~ Ronald Reagan |
Replies:
Posted By: farna
Date Posted: Mar/30/2023 at 9:33am
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Only major difference I know of is that the Jeep version uses a TV cable for pressure control, Toyota uses a computer controlled servo instead of a cable. AFAIK the mechanism in the trans is the same, just what moves it is different (cable vs. servo). There are differences in number of clutches and plates depending on application, like all auto trannys. ------------- Frank Swygert |
Posted By: CamJam
Date Posted: Mar/30/2023 at 9:50am
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Thanks for posting this. I really like the AW4 in my '72 Javelin. Would put one in my '73 as well if I could find a 2WD donor with less than 150k miles on it. ------------- '73 Javelin 360 (current project) '72 Baja Bronze Javelin SST '69 Big Bad Orange AMX (2018 Teague Heritage Award) SOLD  |
Posted By: Trader
Date Posted: Mar/30/2023 at 11:49am
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After seeing the video and looking at this, you wonder about fitting an AW4 on a Gen2 V8. The converter pilot on the AW4 is 1.810" and the Gen1 V8 crankshaft pilot hole is 1.830". Almost like these were made for each other without any expensive adapters. Just thinking out loud. Edit, was thinking about the 67 343 I have but typed Gen1 instead of Gen2.
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Posted By: farna
Date Posted: Mar/30/2023 at 4:23pm
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See https://theamcforum.com/forum/aw4-conversion-by-rick-sc397_topic15549.html" rel="nofollow - https://theamcforum.com/forum/aw4-conversion-by-rick-sc397_topic15549.html . Probably a Gen3 engine, but except for the flexplate it should fit. Might need a thin adapter like the one used with a TH400 in Jeeps. CamJam -- I wouldn't worry much about mileage. Unless it's been seriously abused, especially overheated, the things are as near indestructible (at least behind a 4.0L) as an auto trans can be. Most Jeeps that get parked with an AW4 don't have transmission problems. Mine had about 200K on it when I put it in -- 2002 IIRC. It's well over 200K now and no issues. I'm just running a medium sized engine oil cooler in front of the radiator, no radiator tank cooler. I put about 35K on it from 2002-2007, then about 2K a year 2008-2022 (another 28K). Hopped up 1988 4.0L -- better cam, bored throttle body, late model injectors and intake... about 225 hp (stock 190). In 63 Classic wagon. ------------- Frank Swygert |
Posted By: Trader
Date Posted: Mar/30/2023 at 4:44pm
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Frank, thinking the flexplate would also fit. It would need equally spaced tabs to center it on the OD of the Gen2 crankshaft. The AW4 flexplate is supposed to be thicker/stronger, so welding on a few locating tabs should not be an issue as your welding on a balance weight also. For 0.010" you could loctite in shim stock, depending on fit depth, it would have no were to go. Just looking and being in Canada, finding a 2WD AW4 is not going to be easy. Many 4x4 transmissions here.
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Posted By: CamJam
Date Posted: Apr/02/2023 at 1:12am
Just found one from a '93 2WD Jeep XJ with a supposed 120k miles on it.  Being delivered to my daughter's house tomorrow, as I'm 800 miles away and she's nearby. Going Into my '73 Jav later this year.------------- '73 Javelin 360 (current project) '72 Baja Bronze Javelin SST '69 Big Bad Orange AMX (2018 Teague Heritage Award) SOLD |
Posted By: amcguru
Date Posted: Apr/03/2023 at 3:33pm
All early Toyota versions used a TV cable. Depending on application, some of the units switched to one of three different valve bodies with electronic pressure control. They have a electrically controlled pressure regulator valve attached directly to the valve body and can not be converted to the early tv-cable or installed in an AW4 case. -------------
NAMDRA #3646 "I believe the best social program is a job" ~ Ronald Reagan |
farna wrote:Posted By: amcguru
Date Posted: Apr/03/2023 at 4:23pm
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At moderate power levels, the AW4 is arguably the best automatic transmission you could put behind an AMC engine. The unit uses o-ring seals throughout, torrington bearings in all moderate and high thrust load areas, two center supports, excellent machine work, and a clutch & power flow concept nearly identical to the GM 4l80e, all in a relatively compact package. The unit was built with two different Overdrive ratios (.70 & .75), and two first gear ratios (2.80 & 2.53) which could be mixed and matched by swapping planetary sets during overhaul. With adequate cooling, standard issue A340/AW4 will hold ~350 lb/tq in stock trim. The version used behind the Supra Turbo has a modified valve body, one additional friction in the forward, direct, and overdrive clutch packs, as well as larger/stronger torque converter, and will hold ~450lb/tq in stock form. I am told (but can not confirm) that the turbo version had an additional planet gear in each planetary set, and that V8 applications had the extra clutch disc in the overdrive pack. Trans-go offers shift kits for the AW4, and Raybestos makes a red composite friction kit for added clutch holding power. HD sprags and stand alone controllers are available in the aftermarket as well. The biggest issue I see is the lack of a quality torque converter for a street performance application. There are billet performance options available for Toyota applications, but the crank pilot, mounting pads, and input shaft splines all differ from the AMC version. Perhaps one of the good converter companies could build a custom converter?
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NAMDRA #3646 "I believe the best social program is a job" ~ Ronald Reagan |