67 Cj5 T90C goes into 3rd gear but then no power?

Driving around today....everything was fine on hard surface roads. heard a few "new" clinks in the transmission and then suddenly I had no power in 3rd. down shifted to 2nd and that was ok, back to 3rd and no power. stopped and looked for leaks or anything else unuusal and saw no more that the usual few drops. started up and it happened in 2nd one time but then was normal. Turned around and headed for home and 2nd was fine. Thought I would have to baby her home (10 miles) in 2nd but ended up in 3rd doing ok.....still with the the new "clinks" however. Ideas?
thanks.....
F134 3 speed T90c

 

Loss of power I would think is engine related, maybe a fuel pump starting to go ?

 

Thanks, hadn't thought about that..... Just checked transmission and transfer case fluid levels and they were both ok. Took her out for a drive to see if I could duplicate symptoms and nothing....she ran fine. so potentially not the transmission to your point....We'll check out the pump.

 

Digesting some water in the gas?

 

That would be where I would start. I don't think anything in the trans would cause you to loose power unless its a clutch issue, which I doubt. The higher the gear the more the engine has to work, therefore the more fuel it needs. Just my thought, someone else here might have a different idea. Good luck

 

thanks!

 

I have 68 and it had the same symptoms. Turned out to be fuel tank.

Check out the fuel tank as well. I have a 68 and the tank lining (paint-like sealiant) came lose from the tank. LIkely due to old age and the alcohol that is in the gasoline these days. Also a lot of rust. I used a refirdgerator door gasket (long strip magnet) inserted into the mouth of the tank and found magnet covered in rust.

Removed the tank and used tank sealer kit from Eastwood, but if I was to do it again, I would invest in a new tank instead.

The rust and sealant (the sealant comes off in chunks that reminded me of wet leaves) moved around and would plug the outlet at higher speed (40 or so). The jeep ran fine at lower speeds which didn't use as much fuel. It would starve to a stop. If I let it set for half an hour, it would start ok and run for a mile or so.

I used a temporay setup up with a 6 gallon boat tank to confirm that the problem was just the tank and not the fuel pump/ carburetor.

 

thanks.....was thinking I needed to check the fuel filters (2) in my lines....they could be pretty gunked up if the fuel tank is doing what you are thinking and from John's post above. Jeep sat with previous owner for a few years and I"ve been running it 10-20 miles a week for last 3 weeks I've had it so could be all the mess from inside the fuel tank.
appreciate your suggestion....i'll look into it.

 

Replaced both fuel filters yesterday and she's running like a top! The first one definitely was gunked up.....when I tipped the old one to the inlet side the stuff ran out black. Also took a magnet into the fuel tank but luckily no metalicized particles were picked up. If it happens again we'll dig into that fuel tank....plenty of other to do's on Nelliebell right now! Thanks John, Digger and Pete for your help!

 

I would not rule out the throw out bearing

 

How will the throw out bearing cause the vehicle to lose power in third gear?

 

"Nelliebell" ???

Oh man - I remember that so well. "Whoa, Nellybelle..."

I had (still have) a Tonka Nellybelle, the hood even pops up and down as it rolls along.

http://nyclovesnyc.blogspot.com/2010/07/nellybelle-jeep-from-roy-rogers-and.html




"How will the throw out bearing cause the vehicle to lose power in third gear?"
I suppose he meant maybe if it was mis-adjusted and was making the clutch slip. It wouldn't just be in third, and you'd hear the RPMs rise - but the lower gears do hide it better.

 

no power in third does sound like fuel delivery.

How ever, running up through the gears to get up to cruising speed would use more fuel than just running along in third.

check the fuel filters, blow back through the lines, and check for floating junk in the tank. Or your pump is getting ready to quit on you.

Been there, done that.