TT4?

[Tom S]

What is so wrong about TT4. I test drove one when they first came out and the salesmen said it would out profrome any of the older trucks off road. I never really got a indept tech talk about TT4. This comes up when i have found a really nice yellow 2000 HMCO for 40 grand. For almost te same price there is a nice 98 hard top, which i have heard is the cream of the crop until 03 when the TT4 setup was stopped. Whats is your opinion on this.

[Tom S]

What is so wrong about TT4. I test drove one when they first came out and the salesmen said it would out profrome any of the older trucks off road. I never really got a indept tech talk about TT4. This comes up when i have found a really nice yellow 2000 HMCO for 40 grand. For almost te same price there is a nice 98 hard top, which i have heard is the cream of the crop until 03 when the TT4 setup was stopped. Whats is your opinion on this.

[Webman]

Tom:

The big problem with TT4 is when you hit your brakes it disables the traction control system. The Differential are different than older trucks and do not allow you to BTM the truck. In 2003 they did not eliminate TT4, they just altered the diffs so that you could use BTM, TT4 or also the rear locker. The best off all three worlds.

I have seen many talented drivers use TT4 with out a problem. In order to use it correctly you must keep your rpm steady and not jump on the gas. Many off the hardcore H1 guys have added lockers to the front and rear.

If you dont plan on doing heavy duty off roading I would go with the TT4 truck.

Mark Weber
Webman
www.wisconsinhummerowners.com

[Buckeye Hummer]

Well said webman. I'm still working on a front locker for my '03, any ideas?

Jason

[Webman]

Thanks Jason.

I think you will have to wait until Eaton makes them available. Other then that I am not sure where you could get them. Your other choices are Detroit or ARB. But I would not want two different lockers.

I have not found any situation where I couldnt get over things by not having them.

Being that you have an 03 you have the ability to lock your truck and or use BTM.

If it were me I would wait for the Eaton after market to come out. Not sure when that will be but I have heard they are working on it.

Mark Weber
Webman
www.wisconsinhummerowners.com

[Buckeye Hummer]

That makes sense to me. I heard that AMG effectively releases Eaton from some contract for the front lockers at which time they'll be available to everyone. Currenlty they are only an option on the '04. I know you know this already.

BTM comment, I've been able to get over everything with my rear locked, however, it would be nice to lock the front (BTM) to keep my rear treads from getting chewed up further. Does this sound right to you: Brake on hard, throttle to about 1200-1500 RPM, slowly let off the brake when you feel the front lock? Any more detail from a Pro?

Jason

[Webman]

Jason:

I dont have a rear locker so I cant speak for using BTM along with the locker.

As far as BTM goes. Your thoughts sre correct. You Can feel the truck begin to crawl. I dont think though that I have ever looked at my engine RPM while using BTM. I am no expert on this I just do it by feel. I am just very careful never to let my wheels spin.

You should try using BTM without your locker on and see how it feels if you have not already.

The one thing I have to think is BTM has to be hard on the drive train. I think this is the best argument for lockers. I did break the output shaft on my front diff once while using BTM. Im sure the shaft had been stressed before this but I believe BTM is what broke it. If you go to the following link you can see a video of the breakage, It is at the end of the video.

http://www.wisconsinhummerowners.com/Secret.mov

It is about 115 Megs.

It also has a scene that shows a Humvee with ARB lockers in the front and back crawl up a pretty steep rock face.

Mark Weber
Webman
www.wisconsinhummerowners.com

[Axleman]

Having a different locker in front and rear is not really a problem should you choose not to wait until the Eaton E Lockers are available. An ARB in the front would work fine, but it's either fully locked or completely open, no BTMing. A Detroit SofLocker is a good choice, but in your case you would want it in the rear and put your ELocker in the front. If you live in an area that gets a lot of snow and ice, the Detroit may tend to make driving on the streets a little more interesting.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Joe]

knock on wood, I have not had a problem with TT4. Plenty of rock crawling and the like. Had a slight pulse rate jump once thanks to ABS though. Coming down a steep trail with no place to go and the ABS let the truck go a little further than I would have liked.

Love to get my hands on the elockers. Problem is I keep hearing available soon, seems like for the last year soon.

2001 H1 Opentop

Former 03 H2 Adventure Series

http://homepage.mac.com/babiak1/

[JSA_3]

So, should I have not purchased an '02 w/TT4?

Seems to work very well, though front/rear lockers would be the ultimate.

Webman, are you saying it is not possible to use BTM w/TT4 trucks?

John

----------
'02 HMCO

[Buckeye Hummer]

Webman and Axle,

Thanks for the locker tips. I'm looking in to them.

Webman, nice videos. Thanks for taking the time to post.

Jason

[Axleman]

Joe & John:
That is one of the issues with the system. ABS triggering when you don't want/need it to. TT4 seems to work OK on high traction areas like Moab, etc. Over here where we have mud, loose dirt, gravel, not as well. There were several times over our New years trips where the TT4 trucks could not climb obstacles that the old ones did fairly easily. Driver experience wasn't an issue. Complexity is another issue. I have seem TT4 fail numerous times on the trail for one reason or another, usually due to a sensor that has shifted or become caked with dirt. When that happens, you can still BTM, but it is not nearly as effective as the old trucks because of design differences in the differential carrier. Check the Hummer Info Database on humvee.net for more technical info.

That being said, BTM has it's drawbacks as well. Increased brake wear, increased strain on the driveline, still not 100% as capable as a locker.

Many BTMers will say that BTM has gotten them through most every obstacle they wanted to cross, but everyone I know that has put lockers in (including myself) hasn't regretted it.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[JSA_3]

Is the Traction Control system in the H2 similar to or the same as TT4?

I had and H2 and without the rear dif locked, it behaved very similar to the TT4, supposedly braking the wheel that was spinning. And it was evident when it was operating.

I have not had the opportunities yet to really get a handle on the H1's TT4.

----------
'02 HMCO

[Axleman]

From what I understand, the system is the same in the way it operates, but probably not the same components.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[alecs wife]

http://www.amghummer.com/features/Ea...tonLockers.htm

locker info

Front Locker, Stealth winch, 37" Super Swampers SSR,low center of gravity = Ultimate H2

[HUMMERDOGG]

These may be stupid questions so forgive me for my ignorance regarding the H1. I do not have an H1 but am really interested in getting one in the next year or two. There appears to be two issues with the TT4 hummers- the ABS and the type/ratio of differentials; therefore my questions are:
1)Is there any way to "retrofit" the differentials in a TT4 hummer (2000, 2001, 2002) to replicate the type/ratio that is found in a 1998 hummer or the more improved ratios that are found in the 2003 and 2004 models?... and,
2)Can't you pull a fuse to disable the ABS when offroading? and does this have any undesireable effects while offroading?

If both of these questions can be answered with a yes, haven't I, in effect, made my future 2000/2001/2003 as effective an offroader as the 1998 or 2003 versions?

I look forward to your responses and again, would like to preface these questions with the comment that I know absolutely nothing about the H1 but am working on my knowlede of them.

Again, Thanks for ya'lls help...

-HUMMERDOGG
S&B MEMBER 2003
TROLL POACHER
TROLL TAXIDERMIST

[ssgharkness020147]

HUMMERDOGG,
I have a biased opinon about the 98, seeing as I have one. I dont think you can go wrong with a 98, but here are your other options. There is no way to retrofit the diffs with the torque bias diffs found on the 98. The 98 is regarded as one of the best years for the H1's off-road capabilities, however you can put front and rear locking diffs in an ABS TT4 truck, and it is just as and in a lot of cases more capable then the 98. There is a fuse that can be pulled to disable the ABS, I dont have the ABS system so I am not very familiar on how to go about diabiling ABS. All pulling the fuse will do is allow your brakes to lock up, that is good for some situations and not so ideal for others.

Carey Harkness
1998 HMCO

[Joe]

well, let me throw out some thoughts. I have an 01 TT4/ABS truck and off-road a lot.

I do not believe it is possible to swap diffs, at least without a great deal of expensive and effort that would certainly make in pointless. The best option as mentioned is installing lockers to enhance the capabilities off-road. There are several options. I have been waiting to see if the eaton e-locker becomes available as an aftermarket kit. Hasn't happened yet. This is probably the best solution to improve capability of a TT4 truck

As for the ABS. Not sure about pulling the fuse. The question always is does the ABS fuse also power "other" functions that are critical. The real issue with ABS is on step declines where sliding off a ledge or like presents an issue. I for one have only had the ABS become an issue once on a hill decline. I stopped in plenty of time but it is a very un-nerving experience. Depending on where you wheel the ABS issue may never be an issue. Most of the concerns I've seen are from the folks in the Western States where steep decents are common. In the east is comes up but not often as an issue.

Bottom line is I would explore the locker option and think you will find your truck more than capable to meet all challenges.

2001 H1 Opentop

Former 03 H2 Adventure Series

Homepage:
http://www.hummerh1.net

[Buckeye Hummer]

I haven't experienced any problems with ABS yet and frequent steep climbs and descents. I have found that the gearing has been sufficient to crawl down a hill in Low Locked 1st gear, sometimes too slow. Even with ABS my truck did slide on this decline (they locked) so I hit the gas to correct the rear and the truck righted itself. I've been out with a number of 99-02 H1's and they have all done fine with exception to a couple running with GSA's that would slip going uphill. My '03 has rear locker that has been sufficient for everything I have encountered thus far. It is my opinion that the tires are probably more important than anything and should be considered before lockers. Here's a pic of the slope I was slipping on:

[Joe]

Tires! Your not kidding that Tires make a huge difference. This is the one thing, and easy one, that can make a HUGE difference.

Got to see this first hand during a recent trail ride. There was a fair amount of snow on the ground and one H1 had GSA's. Everyone plowed through all day long except for this poor bastard (jk ). Scrap the GSA ASAP if you plan any off-roading.

2001 H1 Opentop

Former 03 H2 Adventure Series

Homepage:
http://www.hummerh1.net