Broke in MOAB

[Trailabite]

When I'm in 4 low or 2 low everything seems to work just fine. When I go to 4 hi it takes a good bit gas to get my jeep moving. It kinda feels like the brakes are on. I can't get up to speed and after a mile down the road my jeep is over heating, any ideas? I can go 4 wheeling all day and as long as all of the trail are close together I have no issues at all, but when we go from trail head to trail head and have to run in hi gear I have problems.

My specs:
Ramjet 350
TCI T350, with reverse manual valve body
4.3 Atlas
Axle gears 5:38

[Mike]

This is a little out of my league, but I don't want to see a buddy stuck so I am throwing out some thoughts:
Do you have a tachometer? If so, does it change much when you manually shift the tranny up?

I am guessing that it has to be related to the reverse manual valve body. The rest of the specs given shouldn't affect the performance. One more question, how long have you had the manual valve body installed (i.e. have you used it a lot)?

[6spdYJ]

I wouldn't doubt anything in the drivetrain. It all sounds well proven. Try getting on a very slight slope and disengaging the transfer case to see if the rig rolls freely. If it does, put the case in high 2 and the transmission in park. If it doesn't it could be a seized bearing in the transfer case. I would seriously doubt the possibility of it though.
Let's assume it doesn't roll with the case in neutral. That points to the driveshaft u-joints, axle bearings or wheel bearings. Try lifting a front wheel off the ground and spinning it by hand. I have had caliper pistons get cocked in the extended position and drag very bad - enough to not let the rig coast. If they check good, try it on the rear wheels. If they check good, pull one driveshaft and try the slope thing again. If it rolls easily, put it back in and pull the other. Lets assume it won't roll this time. Put in the other driveshaft and pull this one again. Try to drive in 2 hi. If the problem goes away you have narrowed it down to u-joints.
You would be amazed at how much parasitic drag a bad u-joint can cause - or a bad wheel bearing or dragging brake. The fact that 2 or 4 low doesn't affect it indicates that the extra torque is just overpowering a mechanical resistance.

[aw12345]

Sure the exhaust/ cat isn't clogged?

[Trailabite]

We checked all the wheels and the jeep rolls fairly easy. When I checked the fluid level again it was over filled so i drained about 1 qt and I was able to run it in 2/4 hi on several trails and everything seemed to work great. But, when the day was over and we were driving out of the park on a dirt road the hi gear seemed to be going away and my engine over heated again. So I drove it out in 2 lo going about 10 mph. I'm calling TCI in the morning and chat with them and see what they have to say. I'm thinking their torque converter might be bad.

[Trailabite]

Haven't called TCI yet. Trying to check everything else before I do jut so that I can tell them that I already did that. I did check the exhaust, it's all good, no smashed or pinched pipe anywhere and I don't have a cat on it so it's not plugged. I also checked the engine timing and it's right on. I did notice that a few times it would not go all the way into park, I would have to take my shifter back to drive and go back into park for it to lock in. What happens if an automatic is not completely in gear? I'm wondering if when I'm in 3rd or high could I actually be between 2nd and 3rd? Or is that even possible?

[RAT]

Does the transmission make noise at all? Might be losing a planetary set.

[Trailabite]

Does the transmission make noise at all? Might be losing a planetary set.

Nothing, everything sounds good going down the trail. The only time it makes any noises is when it all starts to overheat.

[Lumpy Grits]

Any updates?
LG

[Trailabite]

Any updates?
LG

Work seems to keep getting in the way and I haven't been able to find any time to mess with it. I did take a few minutes just looking around at stuff and now I'm thinking it might just be a heating issue. I used to run my tranny cooler in the back of my jeep (where the back seat used to be) but my complained about the noise when the fan would come on. So I moved it up under the hood and it may be to close to my header. I need to check the fan on the cooler cause it looks like it may be sucking the hot air from the engine and blowing it across the cooler

[Lumpy Grits]

Drain out the fluid-What color is it? How does it smell?
IF it isn't crimson red-Or the oil smells 'burned', that oil(if not the tranny)is done.
You will have flush the torque converter and cooler lines also. Does your tranny use a filter? You may have to drop the pan to find out.
Refill and keep your fingers crossed-I'm sorry to say, I really don't think that tranny is long for this world.
LG

[Trailabite]

I hope it's not fried, that was it's first trip out. I drain about a quart out fluid out of it in Moab and it wasn't burnt and it seemed to have good color. It very well could just be my engine overheating and losing power and making me think its a tranny issue. I need to take it out somewhere and run it with the hood off. I did jack the wheels off the ground and was able to turn them fairly easy, but I think I need try that again but lock the atlas in and see if I'm getting any binding through my drive shafts, I don't there's an issue there but I do check and rule it out.

I need to go get a green sticker so that I can take it out lol

[aw12345]

350 Chevy should have plenty power to push it down the road in high range. If it shifts through the treans gears with the Atlas in high range and you can actually hear each shift without it dogging the engine down or making it run hot. I would surmise that the trans would be ok. Did you do a converter/ trans stall test in gear Atlas in gear brakes set, what rpm can you get the engine up to in that fashion? close to the converter stall speed? If so I would look at ignition timing and cam timing, running excessively lean, low fuel pressure etc

[Trailabite]

350 Chevy should have plenty power to push it down the road in high range. If it shifts through the treans gears with the Atlas in high range and you can actually hear each shift without it dogging the engine down or making it run hot. I would surmise that the trans would be ok. Did you do a converter/ trans stall test in gear Atlas in gear brakes set, what rpm can you get the engine up to in that fashion? close to the converter stall speed? If so I would look at ignition timing and cam timing, running excessively lean, low fuel pressure etc

I have not done the stall test yet and I'm still not sure that it's going all the way into 3rd. On black top I can ratchet through the gears and I can feel it shift through all three gears, but a few times out on the trails it seemed to not shift into 3rd and felt like it was in 2nd or what seemed like in-between 2nd and 3rd. The problem is when would notice this I was already getting hot so I don't what was happening first, if that makes any sense......

[aw12345]

Lock it 1 st redline it then 2nd redline and then 3th. Plenty of desert at Cougar buttes or of Boone rd, to open it up all the way. If need be add a vacuum gauge, will tell ya a bit more what's going on with the engine, or if it has a map sensor read map sensor voltage while doing this.
Start with a stall test, that should pretty much eliminate the torque converter