Topic: knocking in 4wd

[stan98tj]

If i go for the rubi case, i would need to ditch my SYE and driveshaft. I think i get to keep that if i go with the teraflex system. Has anyone used the teraflex, or heard anything about it. I've heard it's a bit loud.

[sharpxmen]

I def have the venerable 4cyl + 3spd auto. So i take it the Rubi is a not an option? I thought the 3spd 4 banger trany had 23 spline like the rubi?

hmm, i don't know in that case, never looked at an auto.

[Jeffy]

If i go for the rubi case, i would need to ditch my SYE and driveshaft. I think i get to keep that if i go with the teraflex system. Has anyone used the teraflex, or heard anything about it. I've heard it's a bit loud.

Yes.  Driveshaft length will probably change and the 241OR does not need a SYE.

The Mepco/Teraflex 4:1 requires some break-in time to quiet down.  Other then that there are no real issues.

[stan98tj]

I talked it over with a shop, a rubi case set up would be about $2100-2300. I could for $1500-1600 do a terra low kit which would allow me to keep my SYE and drive shaft and save a few bucks. According to them, the tera low kit is robust and very effective with increased noise in 4low as its only real drawback. Anyone have any opinions on the teralow kit?

[neale_rs]

The main drawback seems to be you have to be careful not to over rev the Tera Low.   They can get damaged otherwise.

It's better not to go too low with an automatic transmission. I would recommend getting an Atlas with 3:1.   A local Jeep with 4.88 gears, automatic transmission, stock NP231, and 35s could crawl really well, so I can't imagine needing to go much lower.

[sharpxmen]

the rubi already has an sye, you can probably negotiate to get the d/s with the t-case if you get it from a j/y but i'm not sure about the length though (might come to be different in your Jeep, pretty sure it will actually). on the other hand since you have an auto do you really need a 4:1? I mean wouldn't the t/c take care of that if you put it in 1st (i don't think it locks in 1st or 2nd, i might be wrong  but if it doesn't lock i don't see why you need a 4:1 to be honest)

[stan98tj]

the rubi already has an sye, you can probably negotiate to get the d/s with the t-case if you get it from a j/y but i'm not sure about the length though (might come to be different in your Jeep, pretty sure it will actually). on the other hand since you have an auto do you really need a 4:1? I mean wouldn't the t/c take care of that if you put it in 1st (i don't think it locks in 1st or 2nd, i might be wrong  but if it doesn't lock i don't see why you need a 4:1 to be honest)

I just talked to my buddy about this, and I think I'm going to hold off just now on the rubi case. The set up is possible with my transmission and would run me about 2k. He feels I don't really need it given my 4.56 gears. Rubicons did come with autos, however. Currently, I don't really have that "idle/crawl" ability, i end up having to gas up most obstacles. I do still plan to swap the diesel in this spring, so I am holding off on the 4:1 until i see how the diesel acts off road. My buddy felt that I may be geared so low now if I pair with the rubi case that I would be constantly shifting from 4lo to 4hi while on the trail, as staying in 4lo would cause me to rev too high as I moved on the flat spots between obstacles. He also felt hill climbs would be difficult in 4lo as well.

Here are some pics of the carnage. Seems like the case exploded, the chain is off the gears as well, but intact.

[Jeffy]

Does the front driveshaft telescope properly?  Looks like it punched the hole in the transfer case.

[sharpxmen]

Does the front driveshaft telescope properly?  Looks like it punched the hole in the transfer case.

i was thinking the same - looks like somehow the front pushed into the yoke (but the splines should take care of that). or maybe a problem with the CV joint (somehow locked in a position and not allow to angle, what might crack the t-case and maybe explain the knocking). Strange, the only other thing i can think of is if there was wear on one of the shafts or a blown bearing so that the chain climbed the gear teeth, or maybe what Bounty said that was stretched but i don't know if it can be that much longer to go over.

I think a little investigation on the d/s is warranted to make sure it's safe.

[neale_rs]

With the case damaged, you would need a new case first before you could do the Tera Low, that will add more cost to that option.

[Bounty Hunter]

I've got extra rear case halves if you decide on the Tera Low.

Sharp, the chain jumping on the sprockets is pretty common with a stretched chain, usually sounds like somebody hitting the bottom of the tub with a hammer when in 4wd.

[stan98tj]

I've got extra rear case halves if you decide on the Tera Low.

Sharp, the chain jumping on the sprockets is pretty common with a stretched chain, usually sounds like somebody hitting the bottom of the tub with a hammer when in 4wd.

I think i'm gonna pass on the tera low, i've been reading some bad stuff about them. I figure if i do a get a low case, i may as well throw in a Rubi. Now, what i'd like to figure is if the rubi case would actually be too low for my current application: 3spd auto, 4.56 gears and 33s and for my future application which would be a diesel.

[aw12345]

I talked it over with a shop, a rubi case set up would be about $2100-2300. I could for $1500-1600 do a terra low kit which would allow me to keep my SYE and drive shaft and save a few bucks. According to them, the tera low kit is robust and very effective with increased noise in 4low as its only real drawback. Anyone have any opinions on the teralow kit?

If you go to a 4:1 transfercase do yourself a favor and skip the terralo you will be glad you did in the long run. Rubi case or an Atlas is the ticket. Rubi case is an excellent choice oh yeah your knocking noise was the front CV joint. In mud and water country you want to check those regularly since you cannot grease the stock one and once it gets hot it welds itself together and breaks the transfercase.
It a not all that uncommon problem.

[Bounty Hunter]

It's been my experience around here that 4:1 in the t-case is too low for most trail riding.  I see too many jeepers have difficulty finding a tall enough gear for loose or muddy hills, or any obstacle that requires throttle.  I find 2.72:1 and proper axle gearing much more effective.

[stan98tj]

It's been my experience around here that 4:1 in the t-case is too low for most trail riding.  I see too many jeepers have difficulty finding a tall enough gear for loose or muddy hills, or any obstacle that requires throttle.  I find 2.72:1 and proper axle gearing much more effective.

What kind of terrain do you have out by you, Bounty? I'm in CT, northeast is basically rock, muddy trails and hill climbs that can be pretty slippery. I want the best set up and it seems that my buddy was backing your argument. I have to keep in mind that the diesel will have a ton of low end torque, so if i pair it to the Rubi case, it may end up being too low.
If i understand correctly, the issue will be muddy hill climbs, correct? In 4 low with a rubi, i won't be able to spin the tires enough to get traction, but if the hill is rocky on the other hand, ill be able to idle up...