Thump in floor when shutting off 4x4 on 94 Exp

[saskman]

Well my 94 Explorer has been working pretty good but I seem to have an intermittent thump or bang come from under the truck when I shut off 4wd. I always make sure I am not under power when I shut it off but the thump is quite pronounced when it happens, almost like the truck had different tire sizes and it was causing the transfer case to bind. But the tire are the same and there is only a couple thou difference in wear front to back. It needs the transfer case fluid changed but I wouldn't think that would cause this.. Or would it?

Any ideas would be great.

BTW it happens regardless of speed but I seem to notice it more if I am doing around 30 MPH.

 

[Maniak]

What type of ground are you on when you turn off the 4x4?

I don't think I've turned "off" my 4x4 while moving in the last 10 years. I can tell you that when I switch from 4x4 low back to 4x4 back to 2wd I get a hard "clunk" sometimes. It has always done that and I attribute that to driveline bind.

In my case, I'm on dirt but even on dirt I can get some driveline bind since turning puts the left/right and front/back tires in different arcs.

~Mark

 

[bcbid]

I've turned my on and off while moving (city driving), going from snowy roads to dry roads. All I hear is the clicking sound of the transfer case turning on. 93 Explorer

 

[bcbid]

The first thing I would check would be fluid levels. Start with easy stuff first.

 

[saskman]

Thanks for the info. I usually turn it on and off on icy roads and I have done this for years with my other 4x4's with no issues. I am going to change the ATF in the case with Amsoil synthetic very soon as I use it in all my 4x4 transfer cases with good results. So I guess I will wait and see if it helps. Also putting different tires on it next week so maybe they will help.

 

[saskman]

Well, I haven't been driving the Explorer much lately due to the snow on the grid roads being quite deep and the Explorer is too low so we have been using the 2500 4x4. I drove the Explorer home in a storm a couple weeks ago and on the highway it was icy so I had it in 4 high and I guess I came off the ice onto dry pavement (although it was pretty hard to tell) and then I was getting a bang in the front every few minutes and thought the transfer case was going so I shut off the 4wd and the banging stopped. I know driving in 4wd on dry pavement is not good but it shouldn't hurt anything or make noises as long as you are driving straight according to anything I have read. However I put it back in on the dirt road and it worked ok. So that leads me to believe it is a problem with speed difference between the front and rear diffs and as long as there is slip because of bad roads it works ok. (I had the same issue with my 04 Ram 1500 4x4 when I changed the rear tires to a different brand same size just different brand and it started doing the exact same thing, I talked to the dealer and he said it was the tires so I changed the other set and the banging was gone) So I checked and all 4 tires are the same brand and size and pretty close to the same wear, so all that leaves is a difference in ratios front to rear. So I am wondering if someone changed one of the axles and it has a slighty different ratio or what. I need to get it in the air and chek it out but has anyone got any other ideas as to what would cause this. This thing has 3:27 gears in the rear according to the sticker and the tag on the rear diff, I just don't know about the front one. What would the closest front gear ratio be to a 3:27 that is different in a 94?

 

[69Explorer69]

ok i am new to all this 4x4 stuff can i drive with my manual hubs in lock position around town and on the high way with out it hurting anything?? IF not how do i get in to 4x4 while moving under 55mph? i have only needed 4x4 so far in parking lots and if i come across a snow or ice coved rd i pull over and get out and lock the hubs...but its getting old now so i am hoping i can leave them locked and beable to just push the 4x4 when do i use 4x4 low?

 

[saskman]

ok i am new to all this 4x4 stuff can i drive with my manual hubs in lock position around town and on the high way with out it hurting anything?? IF not how do i get in to 4x4 while moving under 55mph? i have only needed 4x4 so far in parking lots and if i come across a snow or ice coved rd i pull over and get out and lock the hubs...but its getting old now so i am hoping i can leave them locked and beable to just push the 4x4 when do i use 4x4 low?

You can leave the hubs locked and just use the button on the dash to put it in 4 high while driving. Dodges kinda do that as they have no type of locking on the front axles at all and they seem to be reliable, just abit harder on gas.

 

[LBarr2002]

You can leave the hubs locked and just use the button on the dash to put it in 4 high while driving. Dodges kinda do that as they have no type of locking on the front axles at all and they seem to be reliable, just abit harder on gas.

Dodges have a vacuum accuated axle disconnect, which explorers do not have.

 

[saskman]

Dodges have a vacuum accuated axle disconnect, which explorers do not have.

Not to start an argument but I had an 04 Ram 1500 Laramie 4x4 and it had no disconnect for the front axles and my 08 2500 4x4 has no disconnects either. Ford uses them on their trucks though. It is a big deal for us Dodge owners as the upgrade to get locking front hubs is over 1800.00. I have discussed this at great length with my service manager at Dodge. So if you have one me and a bunch of guys on the Dodge forums would like to see it. However that being said it would seem the gen 2 trucks may have had them back in the 90's but none of the gen 3 and 4 trucks do.

 

[LBarr2002]

Not to start an argument but I had an 04 Ram 1500 Laramie 4x4 and it had no disconnect for the front axles and my 08 2500 4x4 has no disconnects either. Ford uses them on their trucks though. It is a big deal for us Dodge owners as the upgrade to get locking front hubs is over 1800.00. I have discussed this at great length with my service manager at Dodge. So if you have one me and a bunch of guys on the Dodge forums would like to see it. However that being said it would seem the gen 2 trucks may have had them back in the 90's but none of the gen 3 and 4 trucks do.

I never have (and never will ) own a Dodge, so I'll take your word for it. I've just seen stuff like the Xtreme 4x4 Dodge where they replaced the vacuum disconnect with a cable actuator, and I think there's a build on here of someone using a Dodge axle and blocking of the CAD to use a one piece axle.

I've seen those insanely expensive free-spin hub conversion kits and wondered how it would ever be worth it.

 

[saskman]

I never have (and never will ) own a Dodge, so I'll take your word for it. I've just seen stuff like the Xtreme 4x4 Dodge where they replaced the vacuum disconnect with a cable actuator, and I think there's a build on here of someone using a Dodge axle and blocking of the CAD to use a one piece axle.

I've seen those insanely expensive free-spin hub conversion kits and wondered how it would ever be worth it.

Just a note on those kits, they are more than just the hubs. Dodge, Ford and GM now use unit bearings on the front axle (similar to the bearings used in fwd cars) and all of them are crap when it comes to off roading so these kits replace those with real tapered bearings like the Explorer has, alot of the cost is in the new spindles and stub shafts. These kits are out there for the Dodges and Fords that I know of and the Ford one for the HD trucks replaces the auto hubs with full manual hubs as well. Those unit bearings when they go usually result in a tow job and a 1k minimum bill. The kit can get a Dodge owner up to 2 mpg increase so if the truck is used alot they would pay over time at the price of gas now. Of course that being said I am keeping my 2500 for another year or 2 and getting a 2011 F250 with the 6.4 gasser when I can get a good lease buyback truck.