'92 transmission problem after other repairs
AlexisMachine
10-25-2005, 01:00 AM
Hi, all. This is a strange one, and it's got me baffled. DISCLAIMER: I am *NOT* a mechanic; I only operate on my vehicle out of necessity/desperation, and that's not very often. :D
I've got a '92 XLT 4.0L pushrod w/142K miles, AFAIK original transmission (third owner). Last weekend, I replaced the water pump, upper & lower intake manifold gaskets, and valve cover gaskets. After I got everything hooked back up, I cranked the truck, and noticed several things at once: 1) fuel odor from the engine compartment 2) rough idle (well, rougher than usual; it needs new spark plugs) 3) hard shifting from Park to any other gear. I quadruple-checked the fuel lines; everything tight, no leaks. I checked the manifold bolts; no problem. I checked my vacuum lines; found two broken ones and a third with a hole in it, taped those up as best I could.
What it does now: When I shift from Park to Reverse or any Drive, the xmission kind of "slams" into gear; it's very rough. The truck will not automatically shift in Drive or Overdrive, but I can coax it into gears by shifting between the forward gears, usually starting in 2, then moving to O/D, then cursing at it. After doing all that, it will sometimes auto-shift.
So, my questions are (remember, I'm a novice, some of these might be really stupid):
1) What in the world could I have done during the gasket replacements that would have affected the xmission?
2) The vacuum lines are mostly tiny plastic straws that are now dry-rotted and crumbling. The local auto part stores don't have them specifically. What can I substitute?
3) I drove the truck for about 15 minutes and checked the xmission fluid, and suddenly there's a LOT in there. (By "a lot", I mean the fluid level stops at the second C in the word "Crosshatched" on the dipstick - about, oh, 4-5" from the top of the crosshatched area.) What's an easy way to drain that? Could the excess fluid be causing the shifting problems?
4) The Haynes manual and the instruction sheet that came with the upper manifold gasket said nothing about gasket sealer, so I didn't put any on. Bad idea?
Any help is *greatly* appreciated - TIA!
I've got a '92 XLT 4.0L pushrod w/142K miles, AFAIK original transmission (third owner). Last weekend, I replaced the water pump, upper & lower intake manifold gaskets, and valve cover gaskets. After I got everything hooked back up, I cranked the truck, and noticed several things at once: 1) fuel odor from the engine compartment 2) rough idle (well, rougher than usual; it needs new spark plugs) 3) hard shifting from Park to any other gear. I quadruple-checked the fuel lines; everything tight, no leaks. I checked the manifold bolts; no problem. I checked my vacuum lines; found two broken ones and a third with a hole in it, taped those up as best I could.
What it does now: When I shift from Park to Reverse or any Drive, the xmission kind of "slams" into gear; it's very rough. The truck will not automatically shift in Drive or Overdrive, but I can coax it into gears by shifting between the forward gears, usually starting in 2, then moving to O/D, then cursing at it. After doing all that, it will sometimes auto-shift.
So, my questions are (remember, I'm a novice, some of these might be really stupid):
1) What in the world could I have done during the gasket replacements that would have affected the xmission?
2) The vacuum lines are mostly tiny plastic straws that are now dry-rotted and crumbling. The local auto part stores don't have them specifically. What can I substitute?
3) I drove the truck for about 15 minutes and checked the xmission fluid, and suddenly there's a LOT in there. (By "a lot", I mean the fluid level stops at the second C in the word "Crosshatched" on the dipstick - about, oh, 4-5" from the top of the crosshatched area.) What's an easy way to drain that? Could the excess fluid be causing the shifting problems?
4) The Haynes manual and the instruction sheet that came with the upper manifold gasket said nothing about gasket sealer, so I didn't put any on. Bad idea?
Any help is *greatly* appreciated - TIA!
exploded99
10-25-2005, 04:53 PM
Your tranny has a vacuum modulator which affects shift points. It is vacuum operated - the hose is probably off. So you need to check/replace ALL vacuum lines - yours are obviously in bad shape.
If your tranny is overfilled, you should remove the fluid and get it down to the full line - too much fluid can damage some trannys. Fluid should be a pretty bright red and clear looking. Otherwise, time to change it. Easy way to get some out is to use a suction gun with a long hose on it and suck it out the dipstick tube.
Gas smell - your gas tank vents to a carbon canister under your hood. There is a line from there to your intake manifold. You had it off while doing your repairs. Check the hose, replace it if suspect.
Some of your vacuum lines are hard plastic lines. Most parts stores carry some. Ask them for it. If you need some they can get it in a day or two if they don't stock it.
Never done intake manifold gaskets on that engine - someone else will have to answer the gasket question. Sometimes its ok not to use sealer, most times you want to.
After you have fixed all your vacuum leaks, AND replaced your plugs, post another message if you still have problems with your idle.
If your tranny is overfilled, you should remove the fluid and get it down to the full line - too much fluid can damage some trannys. Fluid should be a pretty bright red and clear looking. Otherwise, time to change it. Easy way to get some out is to use a suction gun with a long hose on it and suck it out the dipstick tube.
Gas smell - your gas tank vents to a carbon canister under your hood. There is a line from there to your intake manifold. You had it off while doing your repairs. Check the hose, replace it if suspect.
Some of your vacuum lines are hard plastic lines. Most parts stores carry some. Ask them for it. If you need some they can get it in a day or two if they don't stock it.
Never done intake manifold gaskets on that engine - someone else will have to answer the gasket question. Sometimes its ok not to use sealer, most times you want to.
After you have fixed all your vacuum leaks, AND replaced your plugs, post another message if you still have problems with your idle.
AlexisMachine
10-25-2005, 07:24 PM
Your tranny has a vacuum modulator which affects shift points. It is vacuum operated - the hose is probably off. So you need to check/replace ALL vacuum lines - yours are obviously in bad shape.
Gas smell - your gas tank vents to a carbon canister under your hood. There is a line from there to your intake manifold. You had it off while doing your repairs. Check the hose, replace it if suspect.
You are a GENIUS. :D
Killed these two birds w/one stone. The vacuum line was disconnected at the transmission - I rehooked it and it shifts just fine! And the fume smell is gone, too. I'm assuming (please correct me if I'm wrong) that that vacuum line connects to the tree @ the intake manifold, and that's where the fumes were coming from. Now, exactly *why* it was disconnected at the *transmission* and not in the engine compartment, I don't know. I'm guessing (again) that maybe it was blown off when I started it the first time after replacing the gaskets; the inside of the hose is a little greasy.
I was too excited about proper shifting to notice the idle. :) I'll get back to you on that after I change the plugs, maybe this weekend. I'll check the auto parts stores for the vacuum lines also.
Thanks again!
Gas smell - your gas tank vents to a carbon canister under your hood. There is a line from there to your intake manifold. You had it off while doing your repairs. Check the hose, replace it if suspect.
You are a GENIUS. :D
Killed these two birds w/one stone. The vacuum line was disconnected at the transmission - I rehooked it and it shifts just fine! And the fume smell is gone, too. I'm assuming (please correct me if I'm wrong) that that vacuum line connects to the tree @ the intake manifold, and that's where the fumes were coming from. Now, exactly *why* it was disconnected at the *transmission* and not in the engine compartment, I don't know. I'm guessing (again) that maybe it was blown off when I started it the first time after replacing the gaskets; the inside of the hose is a little greasy.
I was too excited about proper shifting to notice the idle. :) I'll get back to you on that after I change the plugs, maybe this weekend. I'll check the auto parts stores for the vacuum lines also.
Thanks again!
XLT03
10-26-2005, 12:18 AM
Regarding the greasy little hose to tranny. It's an indication that the vacuum modulator is leaking the the vacum from engine is sucking tranny fluid. Take a look at the hoses that connect to the vacuum tree on the intake mainfold. I suspect that the insides of those hose a also greasy. Pay close attention to the hose that goes to the power brake booster because it's probably also greasy on the vacuum tree end. If yes change it! You don't want that to slip off while driving and have to brake.
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