[87zuke]

Reading YT's post on the T-case made me curious about gear swaps. Even though I don't plan on it now I was wondering if it is better to change the T-case gears or the gears in the front and rear ends? Are there gears that can be swapped directly into the Sammi diffs with out any mods? Thanks. Jim

 

[1507]

First off I need to say that I am surprised that you haven't seen this on the board about a billion times since you registered in 2000. What have you been reading?

Here is what one very reputable vendor has to say about it.

While doing transfer case gears is probably the biggest bang for the buck and a quick-fix, it is definitely a lousy way to try and create a reliable, trouble-free drivetrain. So think about this for a minute...you put on larger tires, so your pinion now becomes TWICE as hard to turn putting TWICE as much stress on the u-joints, transfer case mounts and the transfer case itself, as well as the brackets on the side of the frame that holds the transfer case in place. It leads to problem chasing such as having to use unnecessary large and heavy driveshafts, having the bolts pull out of the transfer case on the long arm side, having the mounting boss break off of the transfer case or having the short arm side bracket start to tear off of the frame rail. It is because you have given your transfer case up to 3 times as much power by putting in lower gears and now the transfer case wants to do flip-flops in its mount. Many people consider only the POWER issue of this equation as opposed to considering the STRESS LOADING situation as well. You need to change the ring and pinion gears also - relative to your tire size - which will make the driveshaft easy to turn again, taking all of the strain off of these parts - just like it was made from the factory when the smaller tires were on it. It is a mistake to do all of your gear reduction at one point. Especially that far up the mechanical chain. Do yourself a favor....reduce the ratio at the ring and pinions relative to the size tire you want to run, then select the transfer case gears that will best meet your 4-wheeling needs. By going this route, you will have a well thought out and trouble-free drivetrain, working well within the parameters of strain that the parts can and will reliably handle.

 

[87zuke]

In reply to:

First off I need to say that I am surprised that you haven't seen this on the board about a billion times since you registered in 2000. What have you been reading?

[/ QUOTE ]

I did a search for diff gears tcase etc etc and found nothing before I posted.Funny thing I have never seen that explaination before. Maybe it was posted and I wasn't really interested at the time. Thanks. But I know people don't follow that advice. Seems most change the t-case only and I was wondering which of the two things would be better and why. Figure the RP would be a much more time consuming but price might be better. Jim

 

[Guest]

It really depends on your budget and what size tires you plan on running. For a 30", 31" and some 32" tires - T-Case gears seem the most cost effective way too go. IMHO one of the nicest thing about the Samurai is when you regear the T-Case you can correct for high range (and not mess with the ring and pinions) and reduce the low range at the same time

Although what Brent (Trail Tough) has published on his site makes a lot of sense - I think that T-Case reduction ONLY has proven to be a reliable, cost effective upgrade. Just be sure to get some good T-Case arms or a bucket (the TT one is awesome) and you will be set. HTH

 

[wildweasel]

Unless you have a cheap line on diff gears then it is cheaper and easier to do the tcase.
While brents party line is correct, I don't see him refusing to sell the tcase gears.

For our low HP usage they seem to hold up fine.
I know how to set up R&P and can do it relitivly quick but I have the tools to make the adapters also. so that keeps the price down alot.

 

[841]

actually bernt does seem to stand behind what he has said if you look at his new line of transfer case gears you will notice the high range reduction is 17% on a 6.5 to one gear set where others are a 24% high range reduction in high on a 6 to 1 gear set and 12% on a 4 to 1 set

so with brents t case gears it is more feasable to gear both the t case and the diffs compared to other manufactures gear sets

 

[Sarge]

Ok , a couple of notes . One, changing out the axle ratios is a good idea , however must be done in moderation . Any tooth count over 4.62 results in a very small pinion gear , I have no idea how guys are getting away with big tires and 5.12+ axle ratios , those pinions are tiny . Also, be aware that if you do regear the axle , you can very quickly go over the rpm limit of the driveshaft at highway speed , trust me on this . A lifted driveline also adds to this problem X10 . The more angle on the shaft , the lower the rpm's it's designed to handle . My cv setup is rated at 5* @ 1,800 rpm's . I run it at 16* @ 3,000 rpm's . No wonder the center ball assembly doesn't last . Also, when you regear the axles you also compound the amount of torque given to the axles themselves , resulting in faster wear and breakage . Up to 31" tires, most of this is a wash , but over 31's and 6" of lift the problems start .
Sarge

 

[Yankee Tim]

Hey Jim,

I've seen this banter a bit, and it's always a question posed along the lines of "T-case OR diffs?".

Well, the best answer is, both. But that'$ not alway$ the an$wer folk$ are $seeking.

Diff gears aren't cheap, unless you have a good line on some, like used or from a yard. Set up, if you don't know how or have a buddy, can be pricey. If done wrong, you can toast your pricey gears quickly. And the taller your gear, like the Kick ones, the less course the grind gets. All gears are a compromise between strength and noise.

Tall Kick gears (5.12s and 5.62s) and hush-hush quite, but that's because of a more smooth grind.

When I say grind, I'm talking tooth count and pitch. This is important when choosing a gear as you can tell there is many ratios very close to each other, say 4.57, 4.62, or 5.12, 5.38 and 5.43, or 5.62 and 5.83 (5.62 very weak, 5.83 very strong).

With that aside, T-case reduction is the ONLY way to reach crawler speed. But, in doing so, increases force on the pinion, which any D30 owner will tell you isn't all that cool. Tiny pinion, like what the Zook has, don't hold up well to added torque. But, the sammy's saving grace is low HP and light weight, which make for a long life with a moderate foot.

I've run the 4.16 case and Kick 5.12s with 33's for a few years now, and you know I would rather idle and crawl and throttle-monger. No problems. But wanting to go deeper (and idle and crawl), I will have an effective ratio out of the t-case of 9.30 to one, and but high range will not be reduced the 18.3%, as that is based on the Sammy tranny, which spins for 3.73's. I'm adding the Kick auto, which spins for 4.62's. Then I also have to add in the torque converter, which will increase the effective ratio again. Oh yeah, then figure in that the tires will increase from 33" to 35".

What's this all mean? Well, a headache when you crunch the numbers over and over for one.

But for me, it means I still need a R&P swap if I want my high range to be somewhere in the ballpark, and it has to be higher than the 4.62 ratio that the auto normally spins. So, as I do my math (which isn't so hot as I did got to a public school), would be in the high 4:1s. But that's not my real concern. The weenie pinion gear, along with a 9+:1 on low range AND torque converter and bigass rubber, is my real concern.

The 4.88's I have from my GV are far stronger than that Kicks 4.62 and 5.12s, and they had to be. V6 power and more weight dictated a stronger grind. Bonus, I have a set when I swapped up to 5.12's in my GV. And don't go there, as I've learned alot about R&P strength since. You know, a good friend named Steve, who really does know a lot about Zooks, tried to teach me about gear grinds and the right way to do it, but I was on my "purist" trip and didn't listen. To sum it up, I've wasted about $1800 in GV drivetrain by NOT listening to him.

me=>

<=what should be done to me

So, for you, now, a gear set should be just fine. Heck, you can pull off 32"-33" tires with just the 5.14s, something that used to require t-case gears. With finese rather than force, you should be fine. Remember, the 3.73 is one helluva strong gear. But bulletproof everything else in the drivetrain. When you got time and money, scrounge up a set of 4.10's, or better, 4.30's from a manual GV as they don't need cans and spacers, and that should make the truck more peppy and better gears, taking some of the load off the pinion.

That help any, or make you as confused as me?

 

[1507]

This is turning out to be a really great thread. I am impressed

 

[Guest]

I agree with what the others have said, very well stated I might add too.
The t-case gears were the single best mod I did. It made 5th gear usable again on the street, and made low range actually low (like a truck). However, as others have stated, this is not the best solution in regards to driveline strength and reliability.

If I had to choose just one, I would do the t-case.

As far as install the t-case gears required less technical knowledge than R&P set up. It was simply replacing parts. All you need is basic hand tools, a shop press, set of bearing jigs, and of course some mechanical knowledge. The R&P install, while not “brain surgery” does require the same tools, plus a dial indicator, and some more advanced mechanical knowledge.

Ideally, I would do the t-case first (when you go 31’s and SPOA) and then do the R&P when you go to the next level. The stock R&P, d-shafts, and U-joints are stronger enough to withstand extended usage with 3.73’s on 31’s.

 

[wildweasel]

Tim if you are going to a kick trans (Auto right?) kicker and 5-1 case DON'T GO DEEP ON THE DIFF GEARS! you will be too low in High High. my 4.10's with the auto/kick/sami 4-1 case is about right for 35's in High high with the 1.6 8v in my rig.
we put randys 35's on my truck this fall and test drove it.
alot nicer on the road than the 33's. This is from actall
test driving.

Of course if thats what you are getting at in your long winded NY sort of way.... then Nevermind.

 

[Yankee Tim]

Yeah, if I wanted to street drive it, I'd go maybe 4.30s...

but it hasen't seen the street, other than trail head rides, and will never again. Right now, it's about low, low, if you know what I mean.

I would do 5.83's, and could sell my 5.12's and 4.88s to cover it, but then I'm back to lesser strength grind. I want as low as possible without sacrficing too much in the pinion strength.

 

[zooky]

with that set up, when you are in low-low you will be in third gear by the time the wheels start turning, making first and second usless, but you will be S-L-O-W. When I drove Glenns, it crawled but if I stepped on the gas it went. It banged through the gears fast but it was usable. Make sure thats what you want. Order the Kicker soon, it takes awhile...

 

[Yankee Tim]

Yeah man. Oh, I'm familiar with the Bam-Bam-Bam of the gears, as the GV has 4.26 cogs. I shift manually. Besides, it's the "use the gas pedal to stay still on a 30* rock face" that I'm after. Auto's make that really easy.

i want to add a manual switch for torque converter lock-up . More drive control. And Bob is saying something about key starting an auto.

Nope, I'm sure about what I want. Been taking my time here, watching others and what works, what could work better, and what is already outdated.

If I wasn't so purist, I would have put Kerry's set up in by now. Far more bulletproof than the Zook stuff, but you know me, I like chrome-plated dung.

 

[wildweasel]

Tim what I am also saying is you need to gear low-low for the tranny. with my setup it is in the sweetspot, I run it in drive in low low so it can shift going up hard obsticals if need be.
I takes a little getting used to, but it makes thing much simpler. I really don't think you should try to go much deeper.
I think you will find the front tcase won't be engaged that much if you do.

 

[Yankee Tim]

I hear what you are saying, and yes, you truck does sit in a very sweet spot.

But dude, it's 9.30 to one. *spoken in that 'But Dad, it's Smokeyyyy." voice from the 70's K-Tel album commercials*

The auto tranny spins 4.62 for 26" tire. The t-case will add a high range reduction, but because it's no longer a Sammy drivetrain, the reduction won't be the 18.3% that the Sammy would get, more like 12% in reality.

Even still, the tire jumps to 35". I know damn well 5.12's would make it riduclous for any short road ride, unless everyone wants to go 35-40 mph, or I rev the piss outta the motor. I have the 4.88's and cost nothing (you remember, I'm Scottish) and they are a improvement strengthwise (not that Zook R&P break much anyhow), but still stronger.

I have a front 4.30, and if the 4.88's seem too much, I could drop down some again.

but like I said, I don't wanna drive it anymore. Trailer to the trailhead will be just fine. And oooooh, 9.30:1. But is what you saying that low/low with auto in 1st will be too low or auto in 3rd (or 4th if I could be so lucky in the donor) would be too low? I can't see D being too low. But that makes me think, maybe I should only settle on the 4-spd, giving me an extra gear speed to chose from?

Damn, was Randy really thinking of 6:1's in his at first?

 

[zooky]

In reply to:

Damn, was Randy really thinking of 6:1's in his at first?

[/ QUOTE ] Yea, but just for a minute, I was gonna use them 'cuz I got them
If you go with the 4-speed, your gonna need the ECM and wire it in, not sure how you would do that with the 1.3 engine

 

[wildweasel]

Low Low 1st is okay for really going ultra slow in a nasty spot. I run Low low drive and let the Auto do the thinking for me. It routinly upshifts going up stuff, where a standard you would be reving the guts out of the engine and still not going fast enough. (one of those impossible to upshift with a standard without braking traction spots..) It does it and you can just worry about your line.

I started off with it in 1st (when you saw me using it this spring) but now I only use first on downhills.

Otherwise it stays in drive. I can go through the gears in Low-Low in about 6' when I punch it.

remember I started off with the GRS2 (4.89) and went back to the 1 so the gearing would be livable all around. (it was way to low on the street/backroads. 40mph was about it)

and I couldn't tell the diff between the GRS1 and 2 in Low low.

I can nudge a rock with my wheels stop and just apply the gas and it raises up the rock like a hydrolic lift.
verryy smooth. I wouldn't go back to a regular setup if you paid me.

The wife calls it the "Easy Chair."

The 4.88's should be okay Just don't go any lower I think it would be a waste of money too.

It is really nice that a concept that I came up with 3 years ago, works so well. (I am not claiming to be the first to think it up, just I came up with it in a vaccum and then found out about the Mike shaffers etc that had done it.)

My drivetrain is now frozen in development and I can finish the suspension tweeks and cage work. Then I will be time to think about WW4! (tube buggy with all I have learned.)
But that is a few years away.

 

[Yankee Tim]

Now, I'm yanking the 1.3. Yeah, after I did all of that. Another thing to Ebay.

I'm looking for an entire donor, that way everything swaps over. 1.6 16v 4spd, hmmmm, like Glenn's....

I wonder it the 4pd is longer due to the OD? I should measure first, huh?

 

[zooky]

In reply to:

I wonder it the 4pd is longer due to the OD?

[/ QUOTE ]
I wouldnt think so, you dont hear of different driveshafts for a 4-speed. Also, the T-case shifter is in the same location regardless of which transmission you have