[Johann]

I have 32" Super Swampers TSL/SX which I use for offroading. Had my G serviced a while ago and my mechanic showed me that all the needle bearings in the gearbox has been flattened like a pancake! He is thinking that the big tires could have something to do with it.
Are there any other things I should be worried about running big tires that could damage my G?

Thanks
Johann

 

[Braingears]

How can the tires do that to your gearbox? I can imagine that you develop more torque on the diffs, but flatten the bearings on your gearbox???
I can also imagine that the gearboxes have been "beefed up" due to the much larger engines in the 463s.

 

[Karl Ingolfsson]

Johann - 1/25/2005 2:38 PM
I have 32" Super Swampers TSL/SX which I use for offroading. Had my G serviced a while ago and my mechanic showed me that all the needle bearings in the gearbox has been flattened like a pancake! He is thinking that the big tires could have something to do with it.
Thanks
Johann

Your mechanic is "right" Johann, -"driving is bad for your car".
-Just park it in a dry shady place, -and it lasts forever... [|)]

Your mechanic can just as well tell you that driving up slope is bad for your gearbox.... and driving upwind is therefore equally bad!
Bigger tires usually cause more wear on brakes, hubs and steering but gearbox life has more to to what happens in front of it -ie engine, clutch and how you shift.
Higher gearing (=bigger tires) makes it necessary to get some more torque out of the engine (or downshift and rev faster) -and therefor into the gearbox.
If the gearbox is the right one for the engine that should not be a problem.
And on non turbo 240D and 300D, -"pedal to the metal" is normal setting anyway.

 

[Johann]

The theory goes as such:
The gearbox normaly do actually move a bit front and back. With the big tires it is not the size but the grip (especially with Super Swampers) which is the problem. Pedal to the medal with wheels that don't slip on a dry surfaces like rock cause the gearbox to move and slam the bearings flat??? Something like that.
On ice, mud etc there should be no problem.

 

[Kerr]

yes the tires can damage stuff but i dont see it hurting a gear box. Axles and diff yes, more weight = more stress...

But a 32 TSL SX Is really only 31.2 tall and 9.9 inches wide if you have 32 11.50 15. for example a stock 02 in my case G500 has 265-60-18's which are 30.0 tall and 10.4 wide, and cause no problems. Im currently running 275-65-18 which are 32 tall and 10.2 wide and have had no problems.


all as one of my frieds what else will cause that, he builds all sorts of race cars and off truck for people.

 

[FernandoRubio]

question?

Johan, never heard of such a diagnosis, but, now I am curious on how well does the 240GD engine moves your 32' tires. Do you run the 5,33 axle ratio?

regards, fernando

 

[Johann]

Fernando I have the om617 300D engine in my 240 with the 5.33 diff ratio. On road it does struggle up hills by getting warmer but off-road it kick @ss!!

A good friend of mine emailed me the following comments:

"About your query on the "Big" tires and cause of your gearbox failure, well it is very difficult to assess the reason, reading in an elderly G-Wagen
magazine, (unfortunately in German) it explains the pro and con about using aggressive and over sized tires on the "G", basically they say that any
aggressive thread or tires bigger than a 75 on a 16" and bigger that a 31 10,5 on a 15" will result on an additional strain on the entire driving train from the gearbox, transfer case, drive shafts,differential and side-shafts, the strain will inflict greater wear and tear to the most weak and vulnerable parts. The diffs are very strongly built so the transfer case, the gearbox is the direct power transfer from the engine torque to the drive train and if that particular bearing was the weak point (through usage, wear and tear)."

The article suggest that the "Big" aggressive tires should be used sparingly and with caution.

 

[FernandoRubio]

OK now. did you have troubles swapping it in? It is one of the upgrades I am considering.
the 240 is very very reliable, as reliable as underpower. I am rrunning 235x75x16 and is alreadya challenge.....

tksfernando

 

[Johann]

It should just be a simple swap. Things to keep in mind is that the 240 have no oil cooler and the 240 oil pump don't have a termostat.
And you'll need the 5 cyl glowing relay, as the 4 cyl relay doesn´t work really great on the 5 cyl.

My daily tires are 235/85/16 which are needed to compensate for the higher revs with the 5.33 diff.

Hope this helps
Johann

 

[FernandoRubio]

Thank you Johan, it does.
Upgrading to the 5-cyl 300D is probably my next change. My current configuration works fine in off-road (I would say just in rock crawling---mud or sand is a disaster), but in a highway is a problem to get to 65-70.
I imagine putting the 300D and a set of 33'' will probably give me 10 mph more of speed, with the same crawling as today, and also some more ground clearance due to the bigger tires....

Just out of curiosity, did you try your 32's with the 240D engine?

tks again.

 

[Johann]

Nope I have'nt. Bought the vehicle after the 300d engine was fitted.
Personally for me the added ground clearance with bigger tires are the biggest advantage.
one guy at our G club only changed his diff ratio on his 240 and were able to keep up with us at 75mph down a mine shaft []
Off-road it was still very capable.

 

[FernandoRubio]

Agree..!

I am in the process of lifting the body just by putting longer springs...probably no more than 2-3 inches.
If I could then swap in a set of 33' instead of my current 30', the combined raise will be close to 4 inches which will be great, but I can put the 33s unless I swap a 300D...the 240 already has a hard time with the 30s, imagine if I put 33s.

I keep looking for a donor to give me a 300D or even a 300TD....

regards, Fernando