• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

'81 Bertone (B28F) BW55 to AW71 swap

TestPoint

Active member
Joined
Jul 15, 2009
Location
Ellijay
I know I am going to have to pull the transmission on my '81 Bertone (B28F) to replace the front pump seal so o o o o I have to ask 'is a trans swap to an overdrive AW71 realistic?'.

The trans only has 25k miles on it but those seals are prone to leak and this one sure does.

The forum search engine sucks.
 
A while back I had looked into doing the same thing. It was my understanding that along with the AW70 you needed a different bellhousing and have the driveshaft made shorter. When I bought my 81 coupe I had the option to have the AW70/71 installed but sadly I did not have the extra funds at the time. The fellow I bought the car from was an all Volvo guy and he said he had done this conversion to few coupes, with all Volvo parts. He was located in Kansas but I have since lost all contact info for him.:-(
 
V-6 Bellhousing for the AW box.... Box was out of a 700 car.

I made the trans mount work.... Weld tabs onto the crossmember so it matches up with holes in the frame rail... Easy.

I'm using the driveshaft out of a M-46 for the V-6 in a 240 (three large U-Joints).... It is just a little short but no biggie... I squeezed it in the center bearing and it works great. Doing it right is making up a front shaft and balancing the complete driveshaft.

Tom your car should have the 'Three Large' U-Joints driveshaft.... If so you can measure with the trans installed for how long the front shaft needs to be.... Take that measurement to the driveshaft shop and they'll make up a shaft for you; balanced and ready to go with new U-Joints.

I supplied power to the solenoid any time the key is on...... Don't need to lock it in third as it never hunts. You could use IPd's block-off plate or do your own enhancement to the plunger.

The AW is a nice box.
 
V-6 Bellhousing for the AW box.... Box was out of a 700 car.
This V6 bellhousing was sourced from what a 760?
 
Use bellhousing from 760/780 V6 83-90. There's one in the JY I'll pull for you if you want. I think you can keep your converter and driveplate (same IIRC).

Converter housing is removable, but different between 3 and 4-speed. Install 240TIC shift kit and high stall converter if you wish as well as 240T police car trans cooler (same as a 740, just with T-static bypass in some years and braided hoses running through the front sheetmetal). Optional with towing package.

Sort out the x-member and driveline, shift linkage is the same. THe Bw/AW55 is 3/4 of an AW7x, just doesn't have the overdrive behind the pump in the converter housing, and has a different valvebody arrangement (obviously).

B280 running on the K-lambda is nice. Would make a nice runner with some B280E heads and machined distributor with the eagle liners and pistons for 3L, as well as some ported eagle exhaust manifolds. They really really revised those engines when they went to even fire and fixed every little stupid nitpick thing on them, except for the gaskets on the cylinder liners, which are always kind of a PITA.
 
Last edited:
Use bellhousing from 760/780 V6 83-90. There's one in the JY I'll pull for you if you want. I think you can keep your converter and driveplate (same IIRC).

Converter housing is removable, but different between 3 and 4-speed. Install 240TIC shift kit and high stall converter if you wish as well as 240T police car trans cooler (same as a 740, just with T-static bypass in some years and braided hoses running through the front sheetmetal). Optional with towing package.

Sort out the x-member and driveline, shift linkage is the same. THe Bw/AW55 is 3/4 of an AW7x, just doesn't have the overdrive behind the pump in the converter housing, and has a different valvebody arrangement (obviously).

B280 running on the K-lambda is nice. Would make a nice runner with some B280E heads and machined distributor with the eagle liners and pistons for 3L, as well as some ported eagle exhaust manifolds. They really really revised those engines when they went to even fire and fixed every little stupid nitpick thing on them, except for the gaskets on the cylinder liners, which are always kind of a PITA.

They even fixed the gaskets for the liners! They became metal. Used in the B-280 and EP/DM engines. I've never had an issue with them...

A three liter on healthy K-Jet IS nice. I had the hole machined in the head for the distributor and gave the distributor the trigger wheel out of a B-30 for even firing pulses.... Perfectly smooth idle and nice power...... I have a distributor gear in the toolbox that will bolt to the end of a B-280F cam for just that! :rofl: Haven't used it in 17 or so years.

Hey we have to chat about a trans oil cooler that you may or may not have.....
 
My 80 262C was done using an 84 760 AW71 originally behind a B28F but any of the V6 AW71s from a 760/780 should do fine. Don't know enough to say if you could adapt a 240 box. Driveshaft looks to be an M46 or M47 one from a 240. Original in-radiator trans cooler (no external, but I would add one). You can either use the OD bypass plate or else install the wiring/relay from a 240 or 760 for OD. Not sure how they did the crossmember, I think it is the original one. Flexplate is stock.
It had the stock shifter setup but I swapped in the 93 240 shifter.
It is all lying on the garage floor if you need any photos. A cylinder liner gasket gave up and it will have three pedals when I'm done with it. Eventually.
The V6 is much happier with an AW71 than the BW55. Its no M46, but I really enjoyed driving mine with the AW71.
 
A cylinder liner gasket gave up and it will have three pedals when I'm done with it. Eventually.
The V6 is much happier with an AW71 than the BW55. Its no M46, but I really enjoyed driving mine with the AW71.

Let me know if you want to make a more amusing engine of your V-6.

It can have a perfectly smooth idle with big naturally aspirated torque. Really moves a Volvo along nice.
 
It is a dark and stormy night . . . and the Alabama - Georgia SEC Championship Game is a real nail biter. I went to Alabama . . . with Joe Namath. That was some time ago.

. . . but I got the PRV bell housing for my AW70 in the mail, literately picked it up at the Post Office. 77volvo245 was cleaning out his stash and found one.

Now I need a 30 gallon steel drum . . . to put the transmission in for rebuild. I have the full GreenBook on the rebuild but no experience to go with it. I discussed rebuild with two different small transmission shops in the area and they both wanted over a thousand dollars with me setting the transmission on their workbench. Clutch disks and all rings/seals kit is about $150.

I figure that I will get a $1000 education over the winter.

[edit] Alabama just won the SEC, on to the National Championship!
 
Last edited:
I've mentioned this before, make sure you have a loooong table to work on. Start at one end, remove a part and place it at the opposite end. And so on and so on. Keeping things in order.
 
It is a dark and stormy night . . . and the Alabama - Georgia SEC Championship Game is a real nail biter. I went to Alabama . . . with Joe Namath. That was some time ago.

. . . but I got the PRV bell housing for my AW70 in the mail, literately picked it up at the Post Office. 77volvo245 was cleaning out his stash and found one.

Now I need a 30 gallon steel drum . . . to put the transmission in for rebuild. I have the full GreenBook on the rebuild but no experience to go with it. I discussed rebuild with two different small transmission shops in the area and they both wanted over a thousand dollars with me setting the transmission on their workbench. Clutch disks and all rings/seals kit is about $150.

I figure that I will get a $1000 education over the winter.

[edit] Alabama just won the SEC, on to the National Championship!

FWIW, there is a low mile M46 for sale with BH down in Texass..... parts just listed last night.
 
What's a year and a few months among friends

Still bored. Covid-19 infection count keeps climbing in the county so we will remain sheltered in place for some time longer.

In a separate thread I went through the difficulty removing the bell housing of the '83 ish' AW70 from a 4 cylinder transmission with the speedometer cable. Most difficult bolts I have ever run into. http://forums.turbobricks.com/showthread.php?t=354596

In addition to the B28F bell housing I had obtained from 77volvo245 I found a AW70 transmission reported in good shape from WREN with the mechanical speedometer connection in the tail shaft. Transmission fluid was still pink and semi-transparent so I think I will just freshen up the external seals and gaskets and hope for the best.

edited-image_26.jpg~original


I had pressure washed the transmission upon arrival home so there is little evidence of leaks but not difficult to do all such standing up. Found on a GOOGLE search an external seals, gaskets, including pan, and o-rings kit for such a project at $30 shipped. Saves trying to part out all the details.

Anyone got a link to a better deal?

What I did not not see was a rear shaft bushing. Is that beyond a normal refresh?

Comments and advice appreciated.
 
Last edited:
Output shaft bushing gets done as needed.
Grab the output flange and reef up an down.
'Clunk clunk?' Is dead. Otherwise leave well enough alone.
Easy to press the bushing out and back in.
 
Back
Top