Driving in 4wd issues

[Evan]

Had a lot of snow up here in Edmonton over the last month or so. I have mostly found that the rear LSD is sufficient for moving me through the stuff, but on slippery nights it's nice to have the 4wd.

 

I notice that when I'm driving on snow covered pavement (still very little traction though) that when in 4wd and accelerating the truck wants to pull to the right all the time, and when coasting it seems to be all over the road. The truck drove fine in 4wd offroad until recently. This is the first time that I've used the truck on road in 4wd. But there are other conditions that may lead to this:

 

1. Recently changed tires from 33x12.5x15 (Interco TSL's) to 33x10.5x15 (BFG Mud Terrains).

 

2. At the same time I changed the tires, I changed the hubs from 1 warn premium and 1 selectro to two Mile Marker Street master (near as I can tell from comparable pictures). The reason for changing them is that the Selectro went Kaboom while trying to pull someone out in reverse in 4 lo. (POSSIBLE DAMAGE TO CV Shaft?)

 

3. When I bought my truck, I received an additional front differential. I'm not sure if this one is the factory one from my truck, or and additional one that they included with the purchase. My thoughts are that the diff in my truck is a replacement, and may have different gearing than the rear. I haven't checked yet, but if you have experience with this then I may have found my solution.

 

I'm leaning towards the damaged CV shaft, or incorrect installation of the hubs leading to one drive tire engaging and the other not, but I could be wrong.

 

If anyone has experience with this themselves, please let me know.

 

Evan. -bounce-

[88pathoffroad]

How's your steering? A shot CL and tie rods or idler arm would make it pull one way or the other in 4WD.

[94extreme]

How's your steering? A shot CL and tie rods or idler arm would make it pull one way or the other in 4WD.

... much more then in 2. that's where i'd start. all of the above + bjs and any other possibly loose stuff. then move on to disassembly if you haven't found an issue. CVs should be inspected by viewing as well as tuggin in every direction possible. if loose then shot. probably would check the new hubs next.. working towards the t-case.. could be the diff also.. at least check fluids in both.

[Evan]

Thanks for the tips. I'll check this weekend.

 

Speaking of Steering components, are the Calmini and L&P CL's made of special steel, or just Mild steel? I have access to all kinds of joints, heims, etc that I could use in the fabrication of a home made CL (fabricator/welder for west edmonton mall and we use all kinds of this stuff in the maintenence of the rides in the amusement park).

 

Cheers,

 

Evan.

[88pathoffroad]

Totally different setups. The Calmini CL is steel stock welded together and the L&P is a stock CL with the jointed sections notched out and spherical bearings and sleeves welded in.

[mws]

Can you elaborate on the "drove fine in 4wd offroad until recently"? If the offroad handling changed as well, there may be something going on. But the rest of your description seems to be typical lack of traction issues.

 

I'll point out that while MT's are great in deep powder, they are notoriously horrible for slushy snow or ice on pavement. They provide very little grip on those surfaces. If you haven't had them siped, at least do that - it will help quite a bit. Of course, a winter tire would be light years better...

 

The all over the road on decel is likely because all 4 tires are slipping. When in 2wd, only the rears are providing engine braking. The fronts are not providing any decel force, so their (limited) traction is not overcome and they can still provide side to side stability. As soon as a tire is slipping or sliding, it can no longer provide side to side grip, so away you go.

 

The pulling to the right on accel is likely due to both fronts slipping and sliding "downhill" on the crowned road. Almost all roads are "crowned" to provide rain runoff. The center is at least a few inches higher than the edges.

 

Your only solutions are to use less accel or decel forces, or get tires better suited for the conditions.

[Evan]

I'll have to go pound the ground away from the pavement soon to see if your theory proves itself. I'll have to take some pics and try for TOTM again.

 

Cheers,

 

Evan.,

[arctic_mark]

Yeah

Had the same experience in the same Edmonton snow. In 4hi it was almost as if the front end would compress down a little, pull to the right slightly, then rebound a bit and pull back to the left. Kind of sea-sick making! This was most pronounced doing about 60-80kmph, In 2hi it was fine. I know it aint a steering link problem as I've replaced thw hole assembly, new BJs, Calmini UCAs etc. AND had the whole thing checked out and aligned at Westend Nissan. May be worn out bearings??? Or just the usual traction issues on half bald Rough Rider ATs from Crappy Tire!!

 

'Nother problem I get is that at around 80kmph in 4hi I get a quiet but distinct howl/whine/whistle from the front dif. Is this normal!!?? Sounds good and propper above and below 80kmph and had no probs when punishing it off road.

 

Mark

[94extreme]

i have a little bit of a whirling sound.. not sure if it's the diff or the t-c though.

[SaKaNa]

I get the whirring noise in 4WD, and its far more pronounced in 4LO, Its just the transfer case's gears.

[mikemike]

hey.. another person from edmonton.. where in edmonton are you??

[Evan]

I'm actually living in sherwood park now, renovating the house in the city. I work at West Ed and Downtown at the citadel, so I'm kind of all over. If you want to get together for a beer sometime, let me know.

 

Cheers,

 

Evan.