Transfer Case Popping - 78 fj40

[jhortonb]

Here are the notes from a previous post. https://forum.ih8mud.com/showthread.php?t=17871

I thought my problem was in the front passenger side. I replaced the right front wheel bearing and u-bolts and the popping remains. After looking into it more, it sounds like it is in the transfer case.

The popping was only happened during take-off from a stop and slightly when shifting gears. Yesterday, I removed the rear drive shaft , greased the u-joints, greased the drive shaft, tightend the output nut on the transfer case output shaft and the rear differential nut. Now the popping is a little louder and more frequent than before. It doesn't make any noises after the initial pop and it drives very smooth at all speeds.

I have read on other posts that it could be the u-joints, output shaft in the transfer case, the bearings in the rear differentials, or an over greased drive shaft. The transfer case was rebuilt less that 1000 miles ago and there was a period that I had to roll start it probably 15 times because of a weak battery and no money.( don't know it this could have caused anything.)

Any help narrowing this problem down would be greatly appreciated!

jb
78' fj40

 

[fsusteve]

Have you checked yer motor mounts and tranny mount as well?

 

[jhortonb]

No I haven't but I will.

 

[fsusteve]

I'm reaching but it can't hurt.

 

[Bailey]

Check out this thread. If your TC does not have the right pre-load you will have slop in the Transmission - Transfer Case that will eventuallly start breaking stuff.

https://forum.ih8mud.com/showthread.php?t=19538

 

[jhortonb]

I didn't do the TC rebuild myself. How can I check to see if this is the problem? What will this slop eventually break?

 

[Bailey]

I'm no expert, but I tryed to rebuild my '77 transmission and transfer case, after all how hard could it be? It's only a few gears and bearings and stuff right? After 2 months it ended up wrecking my idler gear (in the transfer case). The gear shaft had gotten troqued out of alignment. I called up Marlin of Marlin's Crawlers) and he talked to me about the rebuild I had done and at some point he mentioned the preload. I told him I had no idea what he meant by "preload". He then explained how to use a fish scale to measure the preload and how important it was. I realized I was over my head (I've never been qualified to operate a fish scale) and flew myself and transmission/transfercase out to Marlin for some excellent transmission training. If you have any transmission or transfercase questions - he is the guys to talk to, if you need work done I would have him do it.

 

[jhortonb]

I probably haven't actually driven it 300 miles since the Transfer case rebuild and less than 30 since it started popping. Did you have similar symptoms?

 

[Bailey]

Can't remember exactly what it was doing, best way to describe it I guess is that things just felt a little sloppy and continued to get worse. Seemed like there was a bit of a delay then a "bump" when accellerating and shifting up, or braking and down shifting.

 

[65swb45]

Here's any easy, one variable test for the t-case. Block the front tires, raise at least one in the back to unload the powertrain, and rock the rear driveshaft back and forth while the t-case is in hi range. Then shift into lo range and repeat. If the rotation and the clunk are significantly lessened, then you have worn teeth on the hi speed gear, hi-lo shift sleeve and output shaft. Fairly common on 78s. Whoever did your rebuild just didn't look at those parts too carefully, or...............

 

[Reddo]

Here's any easy, one variable test for the t-case. Block the front tires, raise at least one in the back to unload the powertrain, and rock the rear driveshaft back and forth while the t-case is in hi range. Then shift into lo range and repeat. If the rotation and the clunk are significantly lessened, then you have worn teeth on the hi speed gear, hi-lo shift sleeve and output shaft. Fairly common on 78s. Whoever did your rebuild just didn't look at those parts too carefully, or...............

I agree with this, either they didnt look at these parts or they didnt look at all.

 

[jhortonb]

I sure hope it isn't the transfer case. It has causd me lots of headaches. I burned the first TC up out of ignorance (gear oil leak from e-brake). So, I replaced it with a used one from a fellow cruiserhead.

When I went to pick it up at the mechanic, I hear a loud klunk when driving across the parking lot. The case itself busted because someone dropped a bolt down in the TC. The mechanic blamed it on the person I bought it from and vise versa. The mechanic then took the gears from the used one and put them in my old case. It ended up costing me ~$1000. I was able to drive it without any problems for 2-3 months to work and now its having problems again.

I am out of town right now but I will check it out when I get home this weekend. If it is the High-gear or the idler-gear, is it possible to fix it myself? There aren't any Landcruiser mechanics in Springfield, MO that I know of and I don't have much faith in generic (non landcruiser) mechanics right now. I try to work on it myself most of the time but I am kinda nervous about working on the diffs, transmission, or transfer case.

jb

 

[65swb45]

I sure hope it isn't the transfer case. It has causd me lots of headaches. I burned the first TC up out of ignorance (gear oil leak from e-brake). So, I replaced it with a used one from a fellow cruiserhead.

When I went to pick it up at the mechanic, I hear a loud klunk when driving across the parking lot. The case itself busted because someone dropped a bolt down in the TC. The mechanic blamed it on the person I bought it from and vise versa. The mechanic then took the gears from the used one and put them in my old case. It ended up costing me ~$1000. I was able to drive it without any problems for 2-3 months to work and now its having problems again.

I am out of town right now but I will check it out when I get home this weekend. If it is the High-gear or the idler-gear, is it possible to fix it myself? There aren't any Landcruiser mechanics in Springfield, MO that I know of and I don't have much faith in generic (non landcruiser) mechanics right now. I try to work on it myself most of the time but I am kinda nervous about working on the diffs, transmission, or transfer case.

jb

If you are not club shy, there's a group called the Tornado Alley Cruisers that has members in your area. They might be willing to help out a prospective member. Checkout their website, tornadoalleycruisers.com