Blown up... AGAIN [Archive]

Jason

12-18-2010, 04:12 PM

And the saga continues... Two transmissions and now two rear ends have bit the dust thanks to the D24T power. I just blew out the rear end today taking Alex for a ride doing a "performance demonstration"... Blew it up big time too, when coasted to a stop and looked under the car, there was gear oil dripping from the diff! I blew chunks out of the diff cover! If I'm doing it, I'm doin' it right baby!

Off to find another R&P and I guess a G80 limited slip, I don't think the welded spiders were the best idea. I'm thinking they probably got a little bit brittle from the heat during welding since the cool down period wasn't controlled. Hopefully the G80 can hold up to some power, I've heard of more than a few guys over on Tbricks running well into the 13s with them and they haven't had a problem.

Engine is running great!

Jason

verdigo

12-20-2010, 04:51 PM

What does the G80 come out of??

casioqv

12-20-2010, 07:58 PM

v8volvo

12-20-2010, 10:51 PM

Another one bites the dust! :cool:

Sounds like you figured out whatever was causing your smoking and rough running after a cold start on the new motor? Did it just need to wear in a bit, or was it something in the valves or injection?

Jason

12-21-2010, 09:11 AM

Jason- if you have any trouble getting the speedometer to read correctly I can probably help, since I've swapped a G80 into my '87 745 along with the gauge cluster from a 1990 740 and ran into a few elusive problems.

Also, if you're blowing up 1031s left and right, I can't wait to see some dyno numbers on how much power you're making!

Thanks, from what I've found all I need to do is modify the ring down to 12 rather than the 42 or 48 whatever it is. No big deal with a cut off wheel.

The G80 was an optional locking diff that you could get in the 7xx series diesels, and most of the other volvos. They also came in the early 90s cars, which is what mine is comming out of. I forget the series though.

I doubt its making crazy power, but it does run pretty strong.

As for the smoking rough running when cold, I solved that with the block heater! I think its got a couple leaking valves. I'm going to do a leak down test on it and see what cylinders and what valves are doing it. There is next to no blow by now that it has a few miles on it. If the valves dont pound themselves in and seat by springtime, I guess I'll pull the head and try to lap them in, or get them recut if needed. I also need to fiddle with the cold start lever, I have it set up so it fast idles, but I'm not sure its moving far enough forward to really advance the timing. With how the pump is adjusted, the little ball on the lever is moved all the way back and I had to bend the arm on the pump slighly to get it to not touch it at idle when the cold start is off. You barely pull it and it fast idles since its so close to touching. I think I need to modify the arm for more cold start lever travel before it makes contact to increase the idle speed... That may help the cold running as well. With the block heater though, it starts and runs smooth no matter how cold it is outside!

Jason

casioqv

12-21-2010, 10:41 AM

Yea, cutting down the ring is one way to do it. I took the whole axle from the donor without even opening it, and wired up the whole gauge cluster. In hindsight, modifying the tone ring may have been easier.

Jason

12-24-2010, 05:18 AM

I have a G80 and 3.73 R&P on its way after Christmas! Cant wait to get it back on the road, and see how hard it runs with the new engine and 3.73 gear set instead of the 3.54s!

Jason

hvguy

01-12-2011, 11:29 PM

ohhhz my goodnezz, it seems like every diff in the car anyone is building explodes just as you get shit going... fml

the trick to welding the the gears is remove the ring gear, heat up the spiders and goto town! be sure to weld the shit out of it to maximize the weld surface...

saw some guy just weld where the gears meet and it broke on the first burnout lol.

post pics on the new diff! im prob gonna need one.