View Full Version : 780 m90 swap
grandpa960
11-09-2008, 08:59 PM
Hey I'm a volvo enthusiast who came across an amazing find. 1990 780 in very nice shape for its age and i think i can get it for less than a grand. It would be a DD for some time but eventually would end up w. a b230ft fully built w. a dohc. I would love to see an m90 in there or any 5 speed 4 that matter but im not sure if it fits. From what i understand the 780 is the same drivetrain as a 760. So theoretically if an m90 fits into a 760 and the 780 has the same motor and trans....m90 fits in the 780? Can someone please enlighten me on the chassis differences between the 760 and 780? Any and all information is greatly appreciated
Tamnakz
11-09-2008, 09:03 PM
Chassis should be identical, barring differences between solid axle and irs.
BUT, putting an M90 in would cost you around 1k easily, and go BANG once you put some power to it.
Put in a T5. Probably cost about the same, if not less, and will hold ALOT more power.
impulse922
11-09-2008, 09:03 PM
it fits. the m90 comes out of 9 series which are merely updated 7 series.
there is one guy on here that is running an m90 in his 780. he is up in canada land
Tamnakz
11-09-2008, 09:05 PM
Yeah, it'll certainly fit, there's a father/son duo local with a collection of Volvos, among them, each one has a 780 w' an M90.
grandpa960
11-10-2008, 12:46 AM
Chassis should be identical, barring differences between solid axle and irs.
BUT, putting an M90 in would cost you around 1k easily, and go BANG once you put some power to it.
Put in a T5. Probably cost about the same, if not less, and will hold ALOT more power.
My original plan was to weld the 3rd gear stop ring to improve its durability. If i did that you think the t5 would still be stronger?
sweedspeed18
11-10-2008, 02:55 AM
yea the t5 is nearly bulletproof
my friend had one in his 5.0 with like 600hp, and the trans still shifted like it was new, no slips or anything
the m90 is cool if you wanna stay with genuine parts, but if your looking to build, the t5 is the way to go
much less work too, i think the biggest thing about the swap is the driveshaft
i'm not exactly sure where they make custom drive shafts in jersey, although i live in pa
and i don't know where they make them in pa either haha, sorry i know this isn't really helping
n00bs gotta do what they can ahah :boink:
Wagner
11-10-2008, 03:02 AM
BUT, putting an M90 in would cost you around 1k easily, and go BANG once you put some power to it.
Really?
How many gone? How much torque did you have when it let go?
The M90 is stronger than most people seem to think, but it is nothing special when compared to the WC T5. I had the choice of both and have gone for the for the fact that the T5 can be easily and cheaply rebuilt if it breaks and there is massive support for it. If your M90 breaks (& they do, like any gearbox) you'd be looking at importing another one for another grand.
Also, the M90 will not tolerate the seemingly American habit of shifting without using the clutch.
DrvSfly
11-10-2008, 10:27 PM
Dude, definitely get it! Then join the 780 owner's group.
I'd personally go for the t5 swap for a manual.
gm3100
11-10-2008, 10:35 PM
what is the t5 originally installed in?
swede242
11-10-2008, 11:01 PM
The M90 will last just fine as long as you drive it like an adult. With enough ignorance, anyone can blow up anything.
Volvorules
11-10-2008, 11:06 PM
The M90 will last just fine as long as you drive it like an adult. With enough ignorance, anyone can blow up anything.
You know there are adults who race cars, and shift hard?
Just because I drive the crap out of my car doesn't mean I'm ignorant. Actually, sounds like you're the ignorant one.
And to the OP, just get a T5, much easier and cheaper!
Tamnakz
11-11-2008, 12:24 AM
Really?
How many gone? How much torque did you have when it let go?
Me? None.
The guy I know that works at the largest Volvo shop in three states? four.
He has a showcar that the shop funds, they work directly with Volvo and he had been getting NOS M90's direct from the motherland.
This is a stock longblock with a big turbo and 20some pounds of boost.
Even welded, third gear always failed them, until they put a T5 in. . .
growley
11-11-2008, 12:31 AM
You know there are adults who race cars, and shift hard?
Just because I drive the crap out of my car doesn't mean I'm ignorant. Actually, sounds like you're the ignorant one.
And to the OP, just get a T5, much easier and cheaper!
hahaha. Riding and watching you drive the crap out of your car the other day was a testament to the T-5, even though it has been giving you a little bit of trouble lately. I was actually talking to another T-Bricks member who has an M90 in his 940 wagon. He was saying he would rather have a T-5 in his car. Perhaps he'll chime in.
sbabbs
11-11-2008, 12:31 AM
My Getrag is holding fine. You could always put one of those in. I have broke four axles in the last month. I'm done with the welded rearend. I'm going to try a modified 1041 for now.
Simon
Getrag is strong, but ratio's are kinda sucky.
I simply love my M90, it just really needs a short-shifter. I have a few M90's laying around, so if I break one, about an hour later I got a new one under there.
The reason I choose the M90 is because T-5's are hard to find over here (I'm Dutch), and getrag's are more expensive/ hassle then an M90.
Maybe if I wreck a few M90's I will get a nice t-5 from overseas, but looking at linuxman's history they will break too...
swede242
11-11-2008, 09:37 AM
LOL...I rest my case.
Add MS, some stickers and a giant wing while you're at it.
JW240
11-11-2008, 09:51 AM
:drama:
the M90 is strong enough for 11 second 1/4 mile passes (SOME power) in Sweden, seems like a good box to me. It isn't the next M46, it will hold much more. Maybe an early M90 can have its issues.
Fitment is very easy, since everything can be sourced from a European spec 94+ 940, but since you are in the USA a t5 box is cheaper and has the bonus of being rebuild able.
Well thats a big plus for the T-5 indeed, you CAN rebuild it.
Although last time Bozzma brought his M90 to a shop, they did fix it.. hmmmmm
(it had been run without oil, it popped out of gear sometimes, and some other problems)
Big plus for the M90 is indeed fitment, if you have a 740/760 it's sooooooooper easyy to install, for a 200 you need some fabricating skills but it isn't rocket science.
Just choose what you think is best for your setup ;)
@JW; Pass the popcorn please ! :lol:
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