Let me put some of your fears to rest. A Chevrolet transfer case will not bolt up to a Chrysler transmission. The mounts are different too. The round label shows "New Process". That is actually the name of the company that manufactured the transfer case. They make parts for a number of car and truck manufacturers, so it is not uncommon to find internal parts that interchange from one vehicle to another.
As a point of interest, GM manufacturers roughly 80 percent of the parts they use in their vehicles, and they often sell them to other manufacturers. A good example is the MAP sensor and automatic idle speed motor used on your truck. Those come from GM. Chrysler, on the other hand, buys about 80 percent of the parts they use and they make the other 20 percent. They can shop for the best price, and when one supplier cannot keep up production or has a quality problem, they can go to a different supplier. That is why we used to find three or four different manufacturers for half shafts on 1980's front-wheel-drive cars. The shafts from any of the suppliers interchanged on the cars, but parts to repair a half shaft were different. A lot of rear drum brake parts are the same too between GM and Chrysler. Chrysler's turn signal switches in the mid 1990's had three part numbers printed on them. One was Chrysler's, one was Toyota's, and one was for someone else.
The liquid gasket you found could be original. RTV, (room-temperature vulcanizing) sealants have been around since at least the mid 1980's. It was first used on rear differential covers. Now you will find it on engine oil pans, transmission pans and rear covers, and valve covers. The problem with cork or fiber gaskets is that too many of us think that if tight is good, tighter is better. In fact, over-tightening pan bolts often leads to splitting the new gasket, and a leak.
Chrysler has two RTV gasket sealers that I am very familiar with. The first one is black. It cures a little more rubbery and is pretty easy to scrape off, but it has one major problem. It will not bond and seal through a film of oil or transmission fluid. Both sealing surfaces must be perfectly clean and dry. This is a problem for do-it-yourselfers with the older A604 front-wheel-drive four-speed transmissions in cars and minivans. When you do a fluid and filter change, fluid will still be running out of one area even if you let it sit overnight or for 24 hours. My coworkers each had their own preferred method of overcoming that, but my favorite was to reach up into a little well and splash my finger around to get the fluid out. After that, it takes a good minute for that well to fill up again before the fluid runs over and resumes running down onto the flange. I had the pan cleaned up already, and the bead of sealant applied. That extra one minute was plenty of time to spray the flange clean again with Brake Parts Cleaner, wipe it off, and slap the pan in place and get the bolts started. Typing that explanation takes a real lot more time than actually doing the job. The point is, that black sealant works just fine as long as both surfaces are clean and dry.
Chrysler also has a gray sealant that will bond and seal through a light film of oil or transmission fluid, but you still want to try to have dry surfaces. If you happen to overlook a little fluid running onto a sealing surface, you most likely will not have a leak with this gray sealer. It does cure a little harder, and it takes more elbow grease to scrape it off next time. Without going into all the gory details about when my mother ran over a chunk of metal, let me share that I used this gray sealer to build up a patch for the 3" by 4" hole in the side of the gas tank. That "temporary" repair lasted for over 23 years before the rest of the tank rusted out, and never developed a leak.
With both of these sealers, once the pan or cover is bolted tight, you can pour in the fluid right away. You do not have to wait for it to cure first. One more thing to watch for is when you take the bolts out, look for a blob of that sealer on the end by the threads. This is not a problem with factory-applied sealant, but when the rest of us put it on, we tend to put on too much, and some can ooze into the bolt holes. That can make a bolt feel tight when it really is not tight enough to do its clamping yet.
That sealant in your second photo is definitely not a factory job. Being smeared all over like that is not a sign of a professional's work either.
As for the shaking, describe where you feel it and under what conditions. If it is felt in the steering wheel, the best suspect is a front brake that is not releasing properly. Most of the time that is an easy repair. You can identify that by stopping on a slight incline, shifting to neutral, then observing if the truck will creep down-hill on its own when you release the brakes.
If the transfer case is stuck in four-wheel-drive, you will get some shaking when going around corners since the wheels are turning at different speeds. The best suspect for that is the vacuum switch screwed in on top of the transfer case. If the "4WD" light on the dash turns on and off properly, that switch should be working, but there is also a vacuum-operated shift fork on top of the passenger side of the front axle housing. Check the vacuum supply at the two hoses attached to that actuator.
A broken tire belt, bent wheel, and rust or other debris stuck between the rotor and wheel or between the rotor and the hub it is mounted on are other things we will need to consider. This type of shaking is always going to caused by something that is rotating. Worn ball joints, tie rod ends, control arm bushings, and track bar can allow this shaking to be more pronounced, but those parts never cause shaking by themselves. We'll discuss the track bar later. Their common symptom is excessive steering wander.
Here is a link to an article that might give you some more ideas:
https://www.2carpros.com/articles/steering-wheel-shakes-when-accelerating-or-braking
Tuesday, May 11th, 2021 AT 12:32 PM
(Merged)