Quote:
Originally posted by Sean K.:
http://www.pirate4x4.com/forum/attachment.php?attachmen...5&stc=1&d=1143223579
f5fstop,
You make a very valid point especially concerning autos.....however, none of you have actually run a full belly pan, correct? I know several people running them on everything from small SUVs, to buggies to fullsizes....yes, heat builds up more at slow speed without air flow....
What I'm saying is: it's not significant enough to cause a transmission failure, IME. As you eloquently stated: transmission fluid and oils both have ranges of acceptable operating temperature. Unless we did a real test to find out just what the temps are running without a full belly skid and then with....how can ANYONE say for certain it will raise the temperature above the acceptable range? The obvious answer is: you can't. That is just my opinion though and you guys are welcome to your own (not that you need my permission).
I apologize if I ruffled any feathers with my comments. That was not my intent. I was only trying to give my own personal experience with belly pans as well as some general comments about lift height vs. CoG.
Take care,
Sean
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Maybe I should have further qualified my response since it appears to have been missed.
First, I'm talking an H3, and probably goes over to an H2 and H1, but I will be first to state I'm not that familiar with these vehicles.
Second, I'm talking a vehicle with a full body, not a frame unit. It doesn't take a brain surgeon to note that the type of vehicle you are showing in the photos, would have plenty of airflow from top of the vehicle since there is NO body. In addition, heat rises, and it appears there is no place to trap heat and cook the fluid. I don't believe you would be driving this down Interstate 10 at 75 mph, or doing any city, stop and go driving.
I also believe that running rigs like that would tend to blow the trans for other reasons, thus when it is rebuilt, I would hope you would use new fluid.
Now, let me explain something. ALL GM authorized accessories have to be tested by GM.
First, if they affect a safety area, such as a front brush guard, they must be crash tested to assure it has no affect on the front discriminating SIR sensor. Don't want a front brush guard that is so strong, the front sensor does not trigger when required. Someone could get seriously hurt. This means plenty of input from safety engineers, as well as body engineers.
Second, they must not screw with emissions, or else places like CA will come after GM with a big hammer (called a recall). Other states would also be involved like in the NE states. This means input from the emission engineering section in the emission lab. If there are sound concerns, such as an exhaust system, then the requirements for states must be followed.
Third, it must not affect the warranty of the vehicle. In the case of the underbody protection, yes, there was input from the transmission engineering section. Concerns of overheating are stressed. Testing is done on all types of shields, over a long period of time, and then the approvals are given.
Again, any testing is done on the full H3, not an H3 without a body, it has to be a production intent vehicle.
If heat cooking the trans fluid is not a concern of GM (or the owner), then why does the owner's manual state under normal use, the trans fluid must be changed at 100K, but if under severe service it must be changed at 50K:
(h) Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions:
• In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher.
• In hilly or mountainous terrain.
• When doing frequent trailer towing.
• Uses such as found in taxi, police, or delivery service.
These four types of service allow trans fluid to get hot and stay hot, thus breaking down the fluid.
As I said in my previous post, GM assumes (yes this might be an incorrect assumption) that the person who has this underbody protection installed will leave it on the vehicle at all times. They will not install before running a trail, and remove after the trail has been run.
If a person desires a full underbody protection, and installs when required, and removes after, problems with heat destroying the fluid would be minimal (my assumption, not GM's).
For a rig like you show, I'm sure the protection stays on all the time, but again, that will not be used for commuting in rush hour traffic, or at least not on a normal basis.
I will also say that the trail you show looks like a hell of a lot of fun, but I will also state that my H3 will never run it.
Maybe I'm wrong, and I would love to see someone prove me wrong, but I don't believe the H3 is designed to run a trail like that, even with a 2-6 inch body lift.