What type of oil goes in the trans of a 1979 c500-40 clark lift truck . It stopped pulling in forward when warmed up, yet still pulls in reverse. Need to add oil, not sure of the type.

so have you pulled the trans pan to see if any metal in it.it sounds like the sun gear has broke or there is damage inside the trans.id pull pan

any codes ? ussally your cluth pak smooked. need trans

Not sure for 98s. But you need to erase the codes to start. If the problem is still there, Check the wiring to the transmission. You need electrical diagrams.

Upshift cable needs to be checked.

if the car was ok before that hapen posible you have a bad torque converter

Pull the trans & rebuild it

No other option

the car should be warmed up. on a level surface, and it should be driven or at least the trans should be placed in gear (forward and reverse) a few times so that the trans is warned up-with the car in park, pull the trans dipstick (red handle, right side as you face the engine with the hood up)-pull the stick and wipe it off, insert it-the fluid level should be within the cross-hatch marks on the stick, and note the color of the fluid, it should be red-if it is brown or worse, a darker color (like oil), you need to change it.

Saturns are great in that servicing the trans is like doing an oil change in any other car-the trans has a spin on filter (looks like an oil filter) and it has a drain plug, like an engine. They should all be like that...

Out side of a replacement or rebuild your options are limited most all turbos i have had in my 4x4's reverse is the first gear to go out, you can try an additive like lucas or something like that and see, your only out the price of it, but before you do that pull the dip stick and smell the fluid if it smells burnt don't waist you money on the additive and put it tords another trans. or a rebuild.

It sounds to me like your transmission is not well. It's working when the fluid is cold but not as it warms up. Pull the dipstick and check your transmission fluid for color and smell. It should be pinkish and smell like oil. My guess is that it will be closer to brown than pink and have a burnt oil smell to it. It the transmission is full, check the level with the trans warm,engine running, in neutral.I'd be shopping for another transmission. If the fluid is below the add mark, you an usually buy yourself some time on the replacement by changing the trans fluid and filter.At the same time add a transmission treatment with the new oil,I've had good luck with Lucas. Hope this helps.

This is a common problem. You have a cracked forward clutch piston. Ford made this part out of aluminum. The replacements are steel. But you have to disassemble the transmission to install it. ( I know you said Rev too, In the AXODE trans, the forward clutch is on in 1st and reverse)