Auto OD questions

-
C

Charrlie_S

Well-Known Member
Joined
Oct 17, 2005
Messages
4,654
Reaction score
2,762
Location
Silver Springs, FL
Not "A" body, but I respect many of the trans "experts" on here. Purchesed a 1988 D150, 2 wheel drive, to use as a tow vehicle for my race car. Truck has a 360 4bbl, 727 trans. I'm thinking of installing either a A500 or 518 to improve fuel mileage. My old Toyota PU, would get 18-19 MPG towing, so I am spoiled. I know this truck will not get any where near that. I have both the 500 and 518 core transmissions, that need rebuilding. I have rebuilt many 904 and 727 transmissions, but never an OD. I would like recommendations as to which trans (I'm thinking the 518), and any upgrades that should be done, while I'm building. Thanks.
 
Charrlie, I agree with the 518 for towing. As you know it is a 727 with the OD attached to the tail section.A rebuild should be straight foward.I may be incorrect but the early 518 did not use a lockup converter if I remember.I think maybe,, ?? I too have a 88 Ram and have been thinking on doing the same.Hope it all works out and I will follow your lead.
 
Just looked at the trans. I think it may be a lockup. It has the smooth front on the input shaft, and the trans is marked 92-93. I marked it when I got it. I have heard of problems, with these trans, when towing, but figure by this time there are upgrades that can be done.
 
The problems I've read about, are guys towing without switching off the o/d. The rest of the trans is 727. No problems towing with one of them.
 
Hi Charrlie_S,
As Dana indicated above, you would need to turn the O/D off when towing, and therefore would not get any additional gas mileage from the O/D when towing. Also, you could lose some gas mileage when towing due to the additional weight from the O/D. Trust me, when I repeat Dana's comments that the O/D must be off when towing. I made a $2800 mistake by towing our tent-trailer behind our Durango with the O/D on. The A518 had to be completely rebuilt. The torque converter came apart into many tiny particles that were scattered throughout the transmission.

Travis
 
74SwingerSpe said:
Hi Charrlie_S,
As Dana indicated above, you would need to turn the O/D off when towing, and therefore would not get any additional gas mileage from the O/D when towing. Also, you could lose some gas mileage when towing due to the additional weight from the O/D. Trust me, when I repeat Dana's comments that the O/D must be off when towing. I made a $2800 mistake by towing our tent-trailer behind our Durango with the O/D on. The A518 had to be completely rebuilt. The torque converter came apart into many tiny particles that were scattered throughout the transmission.

Travis
Click to expand...
That is what I had heard. I was hopeing there were some upgrades I could do to the trans, to allow towing in OD. If I can't tow in OD, there is no reason to do the conversion.
PS: Trailer weight is 5500 lbs max, and about 1,000 in the bed of the truck.
 
Charrlie, What gears are in the truck ? I will guess 3.55. My 01 Ram 2500 had 3.55 and would not tow in OD.If you would breath on the gas pedal it would down shift out of OD.Was only good going down hill !! I ended up putting 4.10 gears in it when I was racing and towing my car.Now my 88 Ram is a 1 ton and has 4.10 gears.Hardly ever tow anymore and have been debating changing the rear gears or go OD.
 
Dam if that 360 doesn't have enough power to tow in overdrive with 3.55 gears it's pretty sad. My 97 pulled a 25 ft 5th wheel with a 16 ft fibreglass boat behind it with little problem on a level road. Yes it did suck on the bigger hills I had to turn off the od but other than hilly terrain or a big wind it was always in od. Kim
 
Don't know the gears, yet. No tag on the diff, but has yellow marker, like salvage yard part. Getting tires in a couple of days, and will count rotation, while the truck is on stands.
 
You must log in or register to reply here.
-

Back
Top