our 78 f250 is slipping in 4 low. it sounds just like when a clutch slips. put it in high and its fine. any ideas?

 

Which transfer case, 205 (gear driven) or 203 (chain)? No clutches in the transfer case. The 203 shifts in the range box in front of the transfer case and the 205 shifts the gears in the transfer case itself. A 203 might have a bad gear with the teeth slippin or the chain jumping. I'm not familiar enough with them to know. In the 205, it is probably a worn gear or shaft in the transfer case. They rebuild them in half an hour on extreme 4x4 for tv! LOL

BTW, I have a 203 from a 78 Bronco in the garage, but it is for a C6. Got the tranny also.

 

Does it pop when it slips?

 

no pop. just a slight whistle. im not sure if its a 203 or 205

 

I am betting 203 and the chain is slipping.

 

anyone ever rebuilt one?

 

If I had my normal computer I would see if I couldn't find a copy of extreme 4x4 that covers this. Beyond that I don't know enough to really help.

 

I think I have the copy of Extreme 4x4 on my DVR I will have to check.

 

Matt, I dug out my Chilton's for 75-82 trucks and it has a chapter on rebuilding/repair of transfer cases including the 203, 205, and the 208. You probably have a 203 or 205 as noted before.

In reading the discription stuff for the 203, it is a full time 4x4 and does have a "lockout clutch assembly" that allows the transfer case to act like a differential or to lock it for regular 4x4 operation. The transfer case has 5 positions, neutral, high, high lock, low, and low lock.

You can probably check a copy out at a local library, or if you can't find it, I could get a copy to you. Either way the transfer would have to come out for repair.

 

it may be easier to just buy a new one

 

transfer cases are really pretty simple boxes, now I can't say I have personally rebuilt one, but I have watched as someone did rebuild one, and I would bet it would be easy to do.. besides, if you take one apart and put it back together, and it works you learn something new, if you can't, you already have it in your mind that you might just buy a new one, so what are you out?

 

If you need a different one, I'd try to find one at a salvage yard. I looked again and you show the truck as a F250. That makes me think it is probably a 205. Does the truck have manual lockouts? 205's need manual lockouts. If it originally didn't have the lockouts, then it is probably a 203.

The 205 would not be much different to rebuild than a manual tranny.

 

yes manual lock outs, but i dont think its full time. if i remember right, i watched the front drive line not turn when the hubs were out.

also, it only has 4 low high 2 high and neutral on the box.

also, the truck has gears that are too high for its current application, i need a really low first and reverse. besides that, its ok. but it has the bale bed on it and when u back up with 4-7k on its back, it likes to jump out of the gate, which is hard on the clutch

 

If you are in the high range, the gearing would depend on what differential gearing you have. My Bronco has 3:50 gears. 3:73's are real common in 3/4 tons.

If you have the 205 transfer, and that sounds like what you have, in 4x4 low you have about a 2 1/2 reduction from regular gearing. Jack can probably give you the actual numbers. To get lower gearing you probably need to go with lower gears in the diffs. Some aftermarket suppliers do offer lower gears to put in the 205. Another option is to add a doubler. The adapter costs about $700 plus you need a range box from a 203 to add, plus new driveshafts.

Sounds like the 205 is about worn out and needs a rebuild or replaced with a good unit from a salvage yard.

 

Forget fixing it!! Buy an Atlas Transfer Case!!!

Or a Hurcules... 11:1 transfer case!