T-Case or Pumpkin Gears - Off-Road Forums & Discussion Groups
Suzuki GEO All Discussion of all things, Suzuki and GEO

Reply
 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 12-18-2003, 05:41 AM Thread Starter
Keyboard Implanted
 
87zuke's Avatar
 
Join Date: Mar 2000
Location: Southern, Ct.
Posts: 2,747
Thanks: 0
Thanked 0 Times in 0 Posts
 
T-Case or Pumpkin Gears

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
87zuke is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 12-18-2003, 07:17 AM
 
Join Date: Jul 2002
Posts: 937
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

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? [img]images/graemlins/confused.gif[/img]

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.
NC_Zuk is offline  
post #3 of (permalink) Old 12-18-2003, 08:05 AM Thread Starter
Keyboard Implanted
 
87zuke's Avatar
 
Join Date: Mar 2000
Location: Southern, Ct.
Posts: 2,747
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

</font><blockquote><font class="small">In reply to:</font><hr />
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
87zuke is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 12-18-2003, 08:14 AM
pugrocker
Guest
 
Posts: n/a
Re: T-Case or Pumpkin Gears

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 [img]images/graemlins/wink.gif[/img]

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
post #5 of (permalink) Old 12-18-2003, 09:31 AM
Keyboard Implanted
 
Join Date: Apr 2000
Location: western MA. USA
Posts: 3,064
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

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. [img]images/graemlins/cool.gif[/img]
For our low HP usage they seem to hold up fine.
I know how to set up R&amp;P and can do it relitivly quick but I have the tools to make the adapters also. so that keeps the price down alot.

wildweasel is offline  
post #6 of (permalink) Old 12-18-2003, 10:21 AM
 
Join Date: Sep 2001
Posts: 2,009
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

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
szki272 is offline  
post #7 of (permalink) Old 12-18-2003, 10:45 AM
Keyboard Implanted
 
Join Date: Nov 2001
Location: North Central Illinois
Posts: 3,928
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

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
Sarge is offline  
post #8 of (permalink) Old 12-18-2003, 11:10 AM
Keyboard Implanted
 
Yankee Tim's Avatar
 
Join Date: Mar 2000
Location: Northern Catskill Mountains, NY
Posts: 4,756
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

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. [img]images/graemlins/thud.gif[/img] But for me, it means I still need a R&amp;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&amp;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=> [img]images/graemlins/spank.gif[/img] <=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? [img]images/graemlins/40BEER.gif[/img]
Yankee Tim is offline  
post #9 of (permalink) Old 12-18-2003, 11:19 AM
 
Join Date: Jul 2002
Posts: 937
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: T-Case or Pumpkin Gears

This is turning out to be a really great thread. I am impressed [img]images/graemlins/40BEER.gif[/img]
NC_Zuk is offline  
post #10 of (permalink) Old 12-18-2003, 02:14 PM
SilverZuk
Guest
 
Posts: n/a
Re: T-Case or Pumpkin Gears

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&amp;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&amp;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&amp;P when you go to the next level. The stock R&amp;P, d-shafts, and U-joints are stronger enough to withstand extended usage with 3.73’s on 31’s.
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome