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post #1 of (permalink) Old 11-09-2000, 08:29 PM
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GRS Upgrade

I really hate being able to barely hit 55 on a flat surface in 4th. I am starting to think about upgrading to one of Petroworks GRS 1 transfer cases and I have a few questions:

1) How hard is the DIY kit to install for a novice mechanic? Is it woth it to go this route and save a few hundred dollars as opposed to just buying the pre-built 'case?

2) I have 30" BFGs (actually, they are probably closer to 29.5), will the GRS 1 bring me back my power curve or improve it?

3) For those that have them, how do you like it?

4) Are their any other vendors/products I should look at before I make a decision?

Thanks in advance!

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post #2 of (permalink) Old 11-09-2000, 09:12 PM
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Re: GRS Upgrade

Answers to your questions:

1. If you have the right tools it's easy. Hardest part is taking the flanges off the shafts. Go here to see what's involved

2. The GRS1 gives you 12% lower ratio so it'll be right on the money or spin the engine a tad faster.

3. THE BEST!!! I love it to death. Slow and steady.....

4. I had the gears and had them done by Breeze in BC Canada.
As for the rest of the vendors I can't say.

5. Oh thtere was no 5..... I love THEM!!!!

Hope it helps
Pony Express

88.5 5.5" SPOA,8K Warn,4.16's,TuffySkid Plate, Custom bumpers,nerfs.
New>>Now on 33's!!!
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post #3 of (permalink) Old 11-10-2000, 07:05 AM
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Re: GRS Upgrade

I got the rockcrawler from NCO. I really wanted to do it myself but I was not able to get the flange off so I had to take it to someone to do the gears for me. I had a breaker bar with a 4 foot cheater and still could not break it loose. I have 32's on mine with stock R/P front and rear, I was excited to hit 50 in 4th the other day, when I put it in 5th I went down to 45. By the way, the low range is awesome. I didn't think it would be that low, it's like a tractor now.

<font color=green>'96 CHEVY 3/4ton "Headache", 7" Superlift
88.5 Samurai "DONT LAF", 6" of lift, 32x11.5, still coming along, slowly!</font color=green>
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post #4 of (permalink) Old 11-10-2000, 07:40 AM
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Re: GRS Upgrade

Do you think that you Samurai drops down in 5th because your engine is tired or maybe do you think it is just a fact of life with 32" tires?

I have 87 with the 1.3 and had a stock t-case and with stock tires I could do 65mph. Now with 31" tires/SPOA I can still do 65mph (had to calculate the speed using speedo and formula). I have found that you have to leave it in 4th a little longer than before and then shift to 5th to get the engine to pull 5th gear. My next purchase for my Samurai will be a t-case kit too. I am interested in hearing what you have to say about this.

I asked about your engine having enough power because my Samurai only has 68K miles on it. I have been told by another Samurai owner that my engine has quite a lot of punch compared to his. His Samurai has, I would guess over 150K miles, a GRSII and 32" tires.

Tim Martin
87' Samurai, SPOA, 31's, 1" shackle lift, Hi-lift jack, everything else bone stock.
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post #5 of (permalink) Old 11-10-2000, 08:37 AM
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Re: GRS Upgrade

We carry 4.16 gear kits starting at $399. Many also say our instructions are the clearest and easiest to follow in the industry. We also check email every couple hours in case you have any detailed questions that you would like answered. [email protected]
post #6 of (permalink) Old 11-10-2000, 08:55 AM
mike shannon
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Re: GRS Upgrade

i have took the flanges off of 4 differnt t cases. the first one we tried using a breaker bar and a pipe wrench to hold the flanges. that is a bad idea because if your buddie slips the pipe wrench will hit you right in the head. don't ask how i know this. i found that if you put on a good leather glove and use a good impact it will come off pretty easy. just grind yourself a tool to remove the crimp,soak it with some penetrating oil and nail it with the impact. the gear change is pretty straight forward. but you will need a press. later mike

88ht,two87s,88.5 spoa,33X12.50,5.12 f&r,rock cage,4.16 T case
post #7 of (permalink) Old 11-10-2000, 09:57 AM
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Re: GRS Upgrade

If you haven't adjusted your speed to compensate for your larger tires, your 55 mph is really about 62 mph. You should also adjust your mpg accordingly.

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post #8 of (permalink) Old 11-10-2000, 11:13 AM
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Re: GRS Upgrade

i blew my motor(headgasket at fault) 1 month ago. before i blew it though it did 60/65 easy with 31 swamper tsl on it.i was in 4th gear till about 4500 rpm but it would hold 5th. low range sucked for rock crawlin though. i am rebuilding the t-case and regearing the t-case only, 4now. just trying to find the best deal on parts!

build it, break it, then build it better.
post #9 of (permalink) Old 11-10-2000, 11:52 AM
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Re: GRS Upgrade

In reply to Farther:
Actually, I was taking into account the descrepency in the speedometer. I can usually get the needle itself up to about 50 and some change on a good semi flat surface. I figured this is probably about 55mph or just slightly better. Any sign of a hill and I loose all power and can probably hold about 45mph (actual speed). My engine has about 150K on it and I have been trying to replacing things here and there to get it back into shape. A good overhaul would probably help it out tremedously. It was in a lot worse shape than I thought when I originally bought it. But that just gives me an excuse to work on it[img]/wwwthreads_images/icons/wink.gif[/img].

I need to get it back up to highway speeds (65+) as I am going to have to start driving 30 some odd miles to work everyday with it on major interstate. When I first got it I could do just under 70. I still lost power on hills, but it wasn't too bad. Right now, it is ok for around town driving, but I wouldn't dare take it out on a major highway[img]/wwwthreads_images/icons/wink.gif[/img].

post #10 of (permalink) Old 11-10-2000, 03:22 PM
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Re: GRS Upgrade


1. It wasn't that hard to do. The bearings were the nasty part for me.

2. I had 30's with a "baby rocklobster"(I think thats what it's called)and it was good. Both 12 percent under.

3. I love it, makes me feel like I'm cheating.

4. As far as who's to use. This is my only one, so I can't compare. They are all 4.16 I think. I went with the calimini one peice cause, thats what "my" research told me.

I took a ton of pics during the install. Here is a link if you want to see them. They are in order, start to finish

The kit that I got was cool. All new factory gears and stuff. I was impressed. I can't compare though sence this is the only one I have done.

I did the kit for the basic cost, cost of shipping, and I know now how it works now. I like the "I built it" feeling.
Have fun

87 suzuski samurai
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