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Kevin Hans (Kmhans)
New Member
Username: Kmhans

Post Number: 10
Registered: 01-2004
Posted on Monday, February 02, 2004 - 11:27 pm:   Edit Post Delete Post Print Post

Had the chance to put on a set of 235/85R16 wheels and tires off a 110 today and went for a drive.....I was stunned at the difference between the 245/75's that I currently run and the bigger meats. The DI was really laboring along and I definately had to work the 5spd gearbox a little harder than usual. I don't mind running the engine hard, but I don't want to lose to much fuel economy and low range slowness. I want to go big, but I don't want to go any faster in low range than I am now which is too quick. If anyone has these tires with the 4.11 gears...Is the ratio you end up with close to the stock gearing ratio? Ideally a little lower?
Help is always appreciated!
 

Dale Farr (Farrdg)
New Member
Username: Farrdg

Post Number: 11
Registered: 12-2003
Posted on Tuesday, February 03, 2004 - 10:14 am:   Edit Post Delete Post Print Post

Kevin,

I am getting ready to do the same modification. Once you are done the gearing is about 5% lower than stock. The 4.11 gears are 12% lower than stock, which works out great with the 235X85X16 tires. Great basin Rovers has the best parts and gears around. Since the third members have to be rebuilt you might as well put lockers in the front and back at the same time. You will save labor by doing both at the same time. I am going with tru-trac's in the front and rear. The true-trac is a better built unit that the Detroit Locker, but there are differences or trade-off's depending upon what you need. Call Great Basin, they are the best and will sell you only what you need. Keep the shiny side up.

Dale Farr
 

Leslie N. Bright (Leslie)
Dweb Lounge Member
Username: Leslie

Post Number: 2980
Registered: 02-2002
Posted on Tuesday, February 03, 2004 - 11:14 am:   Edit Post Delete Post Print Post

The true-trac is a better built unit that the Detroit Locker


Dale, I want to see the explanation there.....




-L

 

Frank Rafka (Mongosd2)
Dweb Lounge Member
Username: Mongosd2

Post Number: 373
Registered: 02-2003
Posted on Tuesday, February 03, 2004 - 01:07 pm:   Edit Post Delete Post Print Post

I'm curious too, please enlighten us...
 

thom mathie (Muskyman)
Senior Member
Username: Muskyman

Post Number: 572
Registered: 11-2002
Posted on Tuesday, February 03, 2004 - 02:13 pm:   Edit Post Delete Post Print Post

as the ax goes up Frank and Bill ask Dale to stick his neck out:-)
 

Jack Quinlan (Jsq)
Senior Member
Username: Jsq

Post Number: 555
Registered: 10-2002
Posted on Tuesday, February 03, 2004 - 03:07 pm:   Edit Post Delete Post Print Post

can I sharpen that axe for you guys?

Oh suhweet! post #555!

any other team 555 fans out there?
 

Leslie N. Bright (Leslie)
Dweb Lounge Member
Username: Leslie

Post Number: 2989
Registered: 02-2002
Posted on Tuesday, February 03, 2004 - 03:43 pm:   Edit Post Delete Post Print Post

SWRT: SU BA RU! :-)


-L




 

Michael Slade (Tawayama)
New Member
Username: Tawayama

Post Number: 19
Registered: 11-2003
Posted on Tuesday, February 03, 2004 - 05:48 pm:   Edit Post Delete Post Print Post

I did 4:11's, ARB's and 235'85/16's on my LWB RRC.

The gearing is perfect for the engine size (4.2).

Truck also has an ARB bar/winch and an ARB roof rack, so it's no lightweight.

But, the gearing definitely helped offset the increase in tire size.

I went back to 3:54's to see if I could squeeze out some extra mileage (had some diffs laying around and swapped them in). Totally gutless and I took them back out and put the 4:11's in as soon as I could.

This upgrade isn't cheap, but it does work well.

BTW, I always tell my wife that the speedo is 10% high now that I've done it.

;)

Michael
 

David Hill (Davidh)
New Member
Username: Davidh

Post Number: 1
Registered: 11-2003
Posted on Tuesday, February 03, 2004 - 10:17 pm:   Edit Post Delete Post Print Post

I've done 4.11's with 275/65/16's and the gearing is a little lower than stock. With 3.54's it was a bit painful. Worked the engine too hard and ran away downhill in 1st low.
Kind of good for keeping to the speed limits as you're reading higher than your actual speed!
 

Dale Farr (Farrdg)
New Member
Username: Farrdg

Post Number: 12
Registered: 12-2003
Posted on Tuesday, February 03, 2004 - 10:45 pm:   Edit Post Delete Post Print Post

Come at me with those hatchets. Sorry, but here we go. After speaking with the owner of Great Basin here is my explanation. The Detroit locker is a very strong unit but its construction and purpose are different. The Detroit locker is definitely the best source of traction, but not necessarily the strongest. I am told that you should install heavy duty axles with it because it can break the regular axles if you do not, based upon the way it works. I am also told that if you do break an (L/R 24 spline) axle then most likely you will also break the Detroit locker because it is actually not as strong as the Truetrac. The Truetrac has gears in it that are stronger, you actually can twist a L/R axle 190 degrees before it breaks, the interesting point is that if the axle does break, the Truetrac will not break, now all you have to do is replace the axle, you can't do that with a Detroit locker it will also have to be replaced. Note that upgraded heavy-duty axles are the best bet since neither diff will probably break one. You just have to decide what type you want. This is the trade off. Both are good, but both work differently, so you have to decide which is best. That is from the gentleman who sells and builds up third members for a living. That’s my theory and I am sticking too it.

Cheers, let the fighting begin.

Dale Farr
 

Leslie N. Bright (Leslie)
Dweb Lounge Member
Username: Leslie

Post Number: 2993
Registered: 02-2002
Posted on Wednesday, February 04, 2004 - 08:54 am:   Edit Post Delete Post Print Post

That's not what you said, though. Just because there are differences between the Truetrac and the Detroit doesn't mean that one is better built than the other.

I wholly agree, odds are you will regret having a Detroit without upgraded axles. If you have stock axles and break one, yes, you'll probably screw up the Detroit. And true, the Truetrac is less likely to break an axle in the first place.

The Truetrac and the Detroit are two different critters. The Truetrac is a limited-slip diff, the Detroit is a locking diff. The Truetrac is NOT a locker.

The regulars here will always advocate upgrading axles if you're going with a Detroit. You probably won't have a problem with a Detroit if you have the upgraded axles. If you have the Detroit, you will have power to both wheels on that axle, whereas you will still have power to only one wheel with the Truetrac.

Because a Disco is a full-time 4x4, you can't put a Detroit in both ends. You can put a Detroit in the back, and a Truetrac in the front. Or, you could put a Detroit in the back, and an ARB in the front. Sure, you can put Truetracs in both ends if you want: I'm not saying that that isn't better than stock.

But don't shoot down the Detroit with upgraded axles, it's a proven setup.


-L


 

Dale Farr (Farrdg)
New Member
Username: Farrdg

Post Number: 13
Registered: 12-2003
Posted on Wednesday, February 04, 2004 - 10:57 am:   Edit Post Delete Post Print Post

Leslie,

I am not shooting down the Detroit, you are correct it is a proven unit. You are also correct; one is a limited slip, while the other is a locker. The Trutrac still turns both wheels when it is engaged, but it must be engaged, initially that requires a wheel to slip.

I still believe that it is a better constructed unit even though it is not a locker. They simply do not fail and they are also proven. I am in full agreement that the Detroit locker is still the best "locker" out there for the price. I am also fully aware that it is a proven performer with HD axles. Like I said, you have too choose what is right for you based upon the off-roading that you do.

Cheers

Dale…
 

Leslie N. Bright (Leslie)
Dweb Lounge Member
Username: Leslie

Post Number: 2996
Registered: 02-2002
Posted on Wednesday, February 04, 2004 - 11:26 am:   Edit Post Delete Post Print Post

I still believe that it is a better constructed unit

Now, I was all set to agree with you at first, then you went and said that......

Call Bill, call EE, call Rovertym, call anyone who knows these things and ask: both constructed to the same level of craftsmanship. The Detroit is more susceptable to damage if used with stock axles, but that does not mean that it is inferior.

An open diff sends the torque to the side with the least resistance. The TT, being a limited-slip, transfers the torque to the opposite side. If you were where both rear tires have the same amount of traction, or lack of, it'll flip back and forth, but it's not going to drive both tires equally: that's what the locker will do that the limited slip won't.

FWIW......



-L

 

Frank Rafka (Mongosd2)
Dweb Lounge Member
Username: Mongosd2

Post Number: 377
Registered: 02-2003
Posted on Wednesday, February 04, 2004 - 12:36 pm:   Edit Post Delete Post Print Post

They are both well built. Guy's are running TT's front and rear in D2's because of Traction Control, a D1 is much better suited for a Detriot in the rear, TT in the front. This is really mute because it depends what your doing with the truck. Most D2's will benefit more from something as simple aa a way to engage the center lock. That, with Traction Control makes it a very capable vehicle. Getting back to original bone head statement, both are very well constructed, I've broken axles in my Jeep and didn't take out the Detroit. I have seen them grenade, but that comes down to situation.

Frank
 

Randy Maynard (Rans)
Senior Member
Username: Rans

Post Number: 753
Registered: 08-2002
Posted on Wednesday, February 04, 2004 - 12:43 pm:   Edit Post Delete Post Print Post

Installing GBR replacement 3rds front and rear with TT and 4.11's in a few weeks. Also HD rear driveshaft to replace the rotoflex and HD rear axles (to take advantage of the shipping savings more than necessity). Won't be any $$ left for HD fronts for a while! LOL

Just trying to keep up with Frank! LOL
 

Frank Rafka (Mongosd2)
Dweb Lounge Member
Username: Mongosd2

Post Number: 379
Registered: 02-2003
Posted on Wednesday, February 04, 2004 - 12:47 pm:   Edit Post Delete Post Print Post

Watch out for your front drive shaft too Randy...I'm running my stock axles in the front, but I have blown out a CV...
 

Greg Davis (Gregdavis)
Senior Member
Username: Gregdavis

Post Number: 1140
Registered: 08-2002
Posted on Wednesday, February 04, 2004 - 01:02 pm:   Edit Post Delete Post Print Post

Just because you break an axle with a Detroit, doesn't mean you'll lose the unit also. I bought mine from a D-90 owner that broke his rear axle with the Detroit. It's worked fine for me for almost two years now.

Sure, there's the possibility, but it's not a given.

Randy, as far as I know HD front shafts aren't available for us yet. Bill's working on it though.
 

Hendrik Behrmann (Hendrik)
New Member
Username: Hendrik

Post Number: 28
Registered: 09-2003
Posted on Wednesday, February 04, 2004 - 01:09 pm:   Edit Post Delete Post Print Post

Say, what happens to the Detroit when an axle breaks ?

I like the TT for its soft operation. I think that prevents axle failure most times. And, great thing to have in winter conditions. But, of course it lets a tire spin once it is lifted of the ground. And, TracTech says you shouldn´t use it with tires bigger than 32" (about).

The Detroit seems to withstand bigger tires (not ? just MHO) I therefore thought it was stronger. But I wouldnt be happy with its "binary" Operation. I´ve seen a RRC with Detroit installed that wouldn´t unlock it sometimes when cornering. Not a regular fault certainly, but did not help me liking it. And nobody recommends it for the front axle - probably it influences driving behaviour too much there.
I´d would choose a Detroit only in Rover that is merely used for offroading. This is where its strengths are. A TT is better the more tarmac (or sand) the Rover sees. ...

Is anyone using a 3.8:1 3rd member ? This gives a gearing that is just as much higher than stock as the 4.11 is lower. Theoretically the 3.8 gears have stronger teeth.

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