82 2.0 speed info?

[KGR1989]

Alright, so I've had my 82 D50 with a 2.0 for a few months now and it's not given me any problems, but I'm careful about how fast I've been driving it to work because I'm not sure how fast I can safely go without causing any damage. It's a 4 speed manual and I travel about 75 miles a day and 99% of it is highway. It didn't have a tach, so I wired one in and when I'm going 60 it's showing around 3,200 RPM's. Truck didn't have a factory tach, so I'm not sure where the redline is to judge how fast I can go without running into an issue of overheating the oil or foaming up the oil. Anyone have some info for me? Thanks in advance!

[royster]

I've read about guys taching up pretty high, on this forum. I never ran my D-50 above 3,000 rpm.

3,200 sounds a little high for 60 MPH, but you have a 4 speed (mine's a 5) and also a 1st generation (mine's 2nd gen), so I'm not sure. Just thought I'd throw my two cents in.

[geezer101]

That sounds about right for a 4 speed. A 5 speed would put you back to about 2000 rpm @ 60 mph. The redline on these engines is pretty conservative - about the 5,500 rpm mark for peak power and 6,000 redline. The 4G52 is happier to rev than the 4G54 though. The biggest concern is heat - not at cruising speeds but stop/start driving in heavy traffic.

[KGR1989]

Never had any issues with heating up during traffic. The factory temperature gauge still works, but the previous owner installed an aftermarket one as well. The factory gauge always tends to read right at the first mark on the cool side (which is nearly all the way on the low side) and the aftermarket one usually reads around 190 but I've seen it up to 210. I'm not sure where the sensor for it is though vs the factory one. Previous owner also lined up about half the radiator with cardboard and said I should leave it like that so I've got heat.

So since you said the 4G52 is happier to rev does that mean I should be alright to go a bit higher? It would be about 30 minutes straight at a higher rev and my concern would not only be heat, but the oil foaming up possibly. Not sure if that's really an issue on these engines though. I've got an aftermarket oil pressure gauge also and it usually reads 50 at idle and 75 when driving.

[KGR1989]

Also, is it possible for me to swap over to a 5 speed? Not sure if the bolt pattern matches and if 5 speeds are an easy/cheap find. Would the driveshaft I currently have need to be swapped or could I reuse it?

[geezer101]

Absolutely. The 5 speed is available in both narrow and wide mount pattern. I am unsure of what pattern the 4G52 manual engine is though but someone will know and be able to verify. It is worth the swap and should be a straight forward deal. Get one from a truck and not from a different Mitsubishi platform as there are different length extension housings on the gear boxes which will change where the shift lever is positioned.

Some advice - check the tail shaft/drive shaft centre pinion carrier bearing. If it's shot it, will be noisy and cause all sorts of vibrations under the truck.

[KGR1989]

Sweet! I'll definitely look into getting a 5 speed then. I plan on putting it up on the lift sometime in the next week or two. I think the U joint is going bad. Sounds a little bit squeaky when you release the clutch and power is given to the rear. I also need to address the exhaust since it's falling apart haha.

Today I did an oil change, spark plugs, and I was going to do the fuel filter, but I'll save it for when I'm under it on the lift. I'll check the bearing while I'm down there as well.

[geezer101]

There are 2 variations of the drive shaft. What I've figured out is, if you have a drive shaft with the small joints your truck is a half ton - the bigger joints are for the one ton payload.

[KGR1989]

Good info! I still haven't made time to check yet, but I plan on doing it this weekend since I'll have 5 days off.

[pennyman1]

the g52b is a narrow block motor, so find a tranny from a g63b truck. To confirm you have the right tranny, measure from center to center on the lower bell housing holes - it needs to be 12.5 inches for your motor. If the driveshaft is available, get that too just in case if it is a 2 piece one - the front half is where the difference lies between the trannys.