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polishing a turd / aw70-71 build up

n xntrx volvo

Newbie
Joined
Dec 5, 2003
Location
corinth, ms / los angeles
yes i know many have spent lots of money and failed (via level 10)
yes i know there's other options
yes i know i'm asking for a let-down
yes i've rebuilt auto trannies for performance apps (all w/ guides though)
yes i've done research
yes i've got the rebuilding books

now that thats out of the way

goal:
make a aw handle 400hp drag launches

why:
i'm nuts. if it works, it'll clear a major hurdle for most volvo folks

questions:
common performance aw failures? (the 2-3 etc)
using a aw72 converter on a aw72? (2.3 amplification vs 1.8 is why)
diesel clutch pack details? (checked kiwi posts)
removing cushion plate on od drum?
conv amplification formula?
forged foward clutch hub part# 4466343, cant find model used, tranny or vehicle.

plans
aw70-71 bellhousing
aw70-71 tail housing
aw372 aka a44d tranny base (87-89 ram50/d-50, non-lock up, rated at 320lbs stock)
blue plate clutches (r577310 forward/ direct x14, r577320 low/ reverse x5, r577350 od brake x3)
aw71 valve body
spacers in servos instead of springs to raise the pressure
aw72 governor (higher rpm)
aw72 pump (wider)
aw71 gears
external filter set up
synthetic fliuds
reduce drum travel to below min to increase clutch # and decrease eng time
use thinner steels in packs to allow for extra discs
pump, rework the pressure port
weld up a deeper pan for improved consistancy
possible cryo treatments of any reported weeknesses
forward clutch, remove snap ring for extra clutch (as done on some stock)

notes:
no valve body mods planned. prefer to do through other means to reduce pressure on pump
long range project, no funds at this moment. should change shortly.
i'll most likely need to aquire most of an aw72 to go with the aw372 and aw71. will be comparing items as they are disassembled to find the best mix of parts.
not enough budget to get a conv built, plus that'd add more strain on the tranny.
upgrade to higher (numerical) gearing to reduce strain, and improve launch.
will be adding info to this post as needed. just getting it off the memo pads.

fyi:
aw = aisin warner, jap built borg warners
aw's were used by toyota, kia, volvo, suzuki, isuzu, mazda, dodge (mitsu built), and mistubishi (can provide more info to which if needed).
a aw372 is the same as a km148 found in monteros. its the same from the governor to bellhousing. it just happens to have a tranfer case hanging off the back (hmmmmmm 4wd.......)
a version of the aw372 was used in the 4 runner also (89-91 4cyl), called a a44d.
tag number for all is 03-72

general aw notes

stall speeds (engine / rpm)
b17a = 2300
b19a = 2100
b21a = 2200
b23a/e = 2400
b19e = 2500
b21e = 2550
b21f = 2100-2500
b21f mpg = 1800 (aw70)
b21f lh = 1980 (aw70)
b21ft = 2050-2500 (aw71)
b23f = 2200 (aw70)
b27 a/e/f & b28a = 2200 (aw70)
b28e/f = 2300-2400
b20 = 1950
b24 = 2200

wMTI5MDYwMzZzNDEzZGZkMzF5NTQx.jpg


Plower flow chart
gear selector position/gear/ clutch applied/ planetary gear used/ brake applied/ one way clutch applied/ engine braking
wMTI5MDYwMTZzNDEzZGZkMzF5NTQx.jpg


last, but not least:
:nomex:
 
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A stock 700R4/4L60 is better in every way to anything that can be done to the AW70/71. Plus they have the advantage of a very low first ratio that will launch a light car, like a Volvo, like a bottle rocket.

Best of luck on your build up. Proving people like me wrong is the essence of hotrodding.

PS - After my left knee is replaced and surgery for kidney cancer is done, I will be building and marketing adapters for Volvo engines to GM auto transmissions. Probably late this Summer if nothing else goes wrong.
 
ive said this before without anyone listening and i will say it again without anyone listening.

the only reasonable things to do on the topic of using underrated transmissions without any aftermarket is to make the kick down cable be WOT by half throttle and monitor fluid temps like a hawk.

so modify the throttle spool with a larger diameter transmission spool and have the kick down cable itself be on a spring so that it can follow the full range of the throttle.


the kick down trick allows the transmission to always have lots of pressure and to allow it to shift down or up before it is loaded up to high hell.
 
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lol, i love these tranny's, especially my aw71. i am with ya man. i have been researching for stuff to do to it to make them hold. mine is holding just fine though. i found someone to modify the torque converters and insert a forged peice where the stock one strips, or so i have heard. i am looking at the 3000 stall. i will get back to ya if i fine anything out on the trannies. what fails anyways that people are always complaining about? raybestos said that new stock clutch packs will only have a problem above 500hp, and i think that is pretty reasonable, after all, the trannies are pretty old. i am trying to decide whether to make this one last and go through it, have it modified, or a swap, but i would rather keep the aw71
 
ElPiloto said:
A stock 700R4/4L60 is better in every way to anything that can be done to the AW70/71. Plus they have the advantage of a very low first ratio that will launch a light car, like a Volvo, like a bottle rocket.

Best of luck on your build up. Proving people like me wrong is the essence of hotrodding.

PS - After my left knee is replaced and surgery for kidney cancer is done, I will be building and marketing adapters for Volvo engines to GM auto transmissions. Probably late this Summer if nothing else goes wrong.
i remember when the same was said about c4's.
fyi a gm auto requires a good amout of sledge hammering, along with driveshaft and mount work. most people are hessitant to do that. adapting another tranny is cheating to me (unless its a six speed or something not avail in rwd volvos). i got into volvos for the challenge, not the ease.
gearing can be changed. poss going to aw72 gears
aw72 vs aw71
1st: 2.83 vs 2.45
2nd 1.45 vs 1.49
od .69 vs .73
that along with improved rear end gears should help out of the hole.
as for the cable, should have mentioned that, but figured it went w/o saying. kick down will be adj to 1/4 throttle, with some mod'n of the spool (already a frankenstien).
 
I don't ever use a hammer to solve clearance problems. I cut out the tight spot and shape a piece of metal to allow the proper clearance, then weld it in.

A transmission is a transmission. It doesn't matter who makes it as long as it gets the job done. I'm going to use a 10 bolt Buick Grand National rear axle and the 1 piece driveshaft from the same Buick.

As I already said, If I'm proven wrong, I'll be the first to congratulate you.
 
hey man good luck with the tranny upgrades and i promote the idea. AW series trannys are great and can hold up to loads of torque and and abuse. I have found they tend to go south pretty fast when you try to make power above 5500rpm. Eric Simpson blew a 75 shot threw a stock aw71 and loads of boost with a small turbo that pretty much equals loads of TORQUE.. The tranny usually holds up to the 1st to 2nd gear shift its normally the 2nd to 3rd gear shift that kills the tranny... Do what you can to keep the power below 5500 rpm and try to build up that 2-3 shift and it should hold up pretty well for a while.. I run my kickdown cable fairly tight to keep the line pressure up and help the tranny hold up longer..

Sam
 
ElPiloto said:
PS - After my left knee is replaced and surgery for kidney cancer is done, I will be building and marketing adapters for Volvo engines to GM auto transmissions. Probably late this Summer if nothing else goes wrong.
Ooohh.. B21 + T + MS + GM auto + Dana 20 + Willys CJ-3B

Please keep me posted!!!

I'll let you know on the hood soon here.

Good luck to you and my sincere best wishes for your health.
 
I have a 93 AW71 (the late AW71 had better tailshaft bushing location) with MVP high stall converter, Level 10 valve body, B&M 11 x 8 x 1.5 cooler, and Permacool thermostat that I will be selling. It is in the car and running and I don't have time to remove and ship it right now. I'd take $500 for all of the above in a local (NH) deal.

Philip Bradley
 
240Psycho said:
my original AW70 has survived my constant abuse from my F+T

i say go for it, we need more info on these transmissions.

what is the weak link in our AW's?

And I still don't know how you did it! But just like Sam said, it was the 2nd -> 3rd change that broke the back of my car.

Good luck on the AW stuff.

And Phil, I really wish I knew your tranny was for sale a couple of months back. :roll: Oh well...
 
Ooohh.. B21 + T + MS + GM auto + Dana 20 + Willys CJ-3B

Nope. 78 245 + B230ft + MS + 4L60 + GM 10 bolt, 4.30 with Summers Bros. axles.

GM rear axles are not made by Dana. No part of them is Dana or Willys.
 
ElPiloto said:
Nope. 78 245 + B230ft + MS + 4L60 + GM 10 bolt, 4.30 with Summers Bros. axles.

GM rear axles are not made by Dana. No part of them is Dana or Willys.

No!:oops: I was talking about what I want to do with a B21. Although your application is more fun in a straight line. I've got a B21 just sitting here, and with my 5.38 axles in the CJ, thought it would scream with some bigger tires:badboy: (not rock crawling, just access to fishing places)...
 
sam- i'm hearing the 2-3 shift. hopefully the increase in pressures and incresing clutches will help.
also hear the clutch material is plugging up the pump causing it to run dry. so some review of the flow and filtration in that area will need looking into.
why 5500? keep hearing this, without any reason. is it a pump issue or? this is why i'm looking into the aw72 pump. its upgraded, along with being designed for higher rpm (along w/ the gov). what ever differences i find, i hope to repaet again for even more headroom there.

philip- i'd love to open that valve body open to see what was done and find a way to replicate it for other people. i hear the nose of the conv is weak, but have yet to see proof. the higher stall of the 72 guts should be sufficiant. i'd worry about going any higher on stall due to heat. that said, if i could dig it up, i'd be on it, if just for the learning experience. any pictures of the improved rear bush? also, shouldn't a 93 be a aw71L?

El P- not discounting it, or anything else. if sure you've built more then a few trannys. look it over, offer any input.

i'll prob keep the thicker steels. dont want issues with heat disapation and warping. might look into cryo treating these as well.
 
maybe im crazy but....

im fairly certain there is no noticable differance in stall between what my 16 valve car is and what my turbo car was.
 
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