Hello,

I bought a -88 F350 a few months ago and have worked on getting it "in shape" again. I still have some issues that I hope someone can help me with here.

Cruise Control: Does not work and ABS light is on. Changed the Sensor on Differential but no fix. I noticed that 2 Wires that comes from the Cruise Control Box on Left Fender, down to the Transmission are disconnected and hanging under Transmission, but can not find a connection for them.

I'm thinking that's my problem, does anyone have a Electrical schematic on this?

Speedometer is off by 5Mph, can I just replace the "plastic gear" on the Speedo Cable, if so, where doI get it?



The truck sucks the fuel, only 6-7 Mpg not towing. Engine seams healthy, does not smoke, No fuel leaks. Any suggestions? Worn IP, Bad Injectors?

Almost Done....

On the same topic, in order to get better milege, is there a way to hook up an Overdrive to the C6 Transmission, if so, where do I get it?

Great forum, hoping someone can help.

COBA

 

I can't say much about the cruise, I don't recall the two wires to the tranny. I have the same ABS problem, I haven't done anything about it, but most say changing the sensor is the fix. Maybe someone else has another idea.

As for the overdrive, I have the same truck, 88 F350 7.5 extcab. I bought mine with the Gear Vendors overdrive already in place. It bolts to the rear of the tranny and has a control box inside the cab. You hit a switch to activate then it's completely automatic after that. The options are to engage @ 20 or 40 mph. I use the 40 mph and it kicks in by itself and has a light showing it's engaged. It drops the rpm @ 55/60 by about 400~500. I don't drive it now as it's still a project, but it did seem to get in the 10mpg range, but that was only one tank check.

The GV unit cost in the $3000 range and requires a chage to the drive shaft length. It's a great unit but I'd consider changing gears first. If you don't need all the pulling power you have with current gears, consider changing over to a higher gear. I think mine is a 410 gear and if yours is that low, maybe something in the 350 range would be a better choice. If you not towing, you don't really need the real low gears.

Another option is the AOD tranny, should be in the early/mid 90's trucks. They have a bad rep, but if properly built should hold up pretty well. I don't know about the cost of a rebuilt tranny, if it's in the 2500 range, the the C6+GV might be a better option, as the C6 is well know as a tough unit.

Check eBay for GV units, I've seen them in the $900 range before, just make sure you know the numbers as they have different units for different applications. Also you'll want a COMPLETE setup, cables, wires, control box ...

-KarlJay

 

6-7 mpg is what I get, 88 f-350 4x4 C6 4:10, loaded or empty...

gregfire