Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

flat towing question

Old Jan 14, 2011 | 10:27 AM
  #1  
stereoguy's Avatar
Thread Starter
Registered User
 
Joined: Sep 2009
Posts: 199
Likes: 9
From: michigan
flat towing question

I have heard it is bad to flat tow your truck without disconnecting the drive shaft. Why? And what will it do? I have the Marlin dual case setup, couldn't I just put everything in neutral?
Reply
Old Jan 14, 2011 | 10:30 AM
  #2  
waskillywabbit's Avatar
Banned
iTrader: (-1)
 
Joined: Jul 2003
Posts: 3
Likes: 20
Ask ocdropzone about doing such things. He learned the hard way.

:wabbit2:
Reply
Old Jan 14, 2011 | 10:37 AM
  #3  
stereoguy's Avatar
Thread Starter
Registered User
 
Joined: Sep 2009
Posts: 199
Likes: 9
From: michigan
normally I use a car/truck dolly . So only the rear wheels are on the ground , is that Ok? My truck has a spool in the rear too ,should I be disconnecting the rear driveshaft?
Reply
Old Jan 14, 2011 | 10:39 AM
  #4  
waskillywabbit's Avatar
Banned
iTrader: (-1)
 
Joined: Jul 2003
Posts: 3
Likes: 20
Cliff notes: Do not flat tow without removing the rear drive shaft or you'll be sorry.

:wabbit2:
Reply
Old Jan 14, 2011 | 10:40 AM
  #5  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
nope that would be the same thing towing the truck flat with the hubs unlocked.

IIRC it has something to do with the way the transfercase bearings are lubricated and the engine has to be turning the front transfercase bearings in order to lubricate the rear transfercase bearings. Since the engine is not running the rear bearings of the transfer case would not be getting lubed but would still be turning even with the transfer case in N.

If I am wrong please someone correct me.

I think for this same reason is why it's not good to drive downhill with the clutch in or the transmission in neutral.

Last edited by xxxtreme22r; Jan 14, 2011 at 10:44 AM.
Reply
Old Jan 14, 2011 | 10:41 AM
  #6  
E-ROC's Avatar
Registered User
 
Joined: May 2010
Posts: 432
Likes: 0
From: Hemet, CA.
always pull the driveshaft. without the vehicle running in gear the gears cant fling the oil to all parts of the t-case or tranny. this is twice as good to do if you use a dolly for that tiny chance that your t-case jumps to 4 wheel drive. that would be a disaster to see!
Reply
Old Jan 14, 2011 | 10:44 AM
  #7  
waskillywabbit's Avatar
Banned
iTrader: (-1)
 
Joined: Jul 2003
Posts: 3
Likes: 20
Yep. Still turning even in neutral but without lubrication tcase bearings go boom, wallet goes pow, unhappy camper

Remove rear dshaft or full floater rear with manual hubs

:wabbit2:
Reply
Old Jan 14, 2011 | 10:48 AM
  #8  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
on a side note, with your rear case in N your front case will be safe, but not the rear one.
Reply
Old Jan 14, 2011 | 10:51 AM
  #9  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
what I am curious about if I am thinking correctly, is if the rig has ADD and the xfercase is in 4wd when flat towing, since the one front cv shaft spins all the time if it's safe to tow, at least on the transfercase. Or does the transmission has the same type of issue without the engine turning.

Or am I completely wrong thinking the one ADD shaft spins full time to begin with.


EDIT: would this be the same case if the trans is in N and the front hubs are locked and the x-fer was in 4wd? Although I know it's not a good thing to be in 4wd on a high traction surface either.

Last edited by xxxtreme22r; Jan 14, 2011 at 10:54 AM.
Reply
Old Jan 14, 2011 | 11:05 AM
  #10  
MudHippy's Avatar
Registered User
 
Joined: Jan 2007
Posts: 6,106
Likes: 27
Well, I've gone over my notes carefully and have come to a conclusion. This only applies to the transfer cases that I have a full working knowledge of, having disassembled and rebuilt mine on a couple of occasions. That would be the VF1A or VF2A, mine's a VF1A but the VF2A is nearly identical. I have almost no knowledge of the inner workings of gear drive transfer cases, so this may or may not apply to those.

Both the VF1A and VF2A are chain drive, and both have an oil pump that's driven by a sprocket on the transfer case input shaft. The only way to prevent the input shaft from turning in relation to the output shaft, and thus preventing the oil pump from being driven, is to put the transfer case in neutral. So if you were to leave the transfer case in gear(ie 2H, or 4H/4L with the hubs unlocked) while being flat towed(or towed on a front wheels only dolly), and put the transmission in neutral instead, the oil pump will still pump oil to all the bearings and other parts that need lubricated while the transfer case is in operation.

I had no time to think this through when I towed my rig on a dolly some time ago, so I went ahead and removed the rear driveshaft as a precaution.

Last edited by MudHippy; Aug 19, 2012 at 02:32 PM.
Reply
Old Jan 14, 2011 | 11:23 AM
  #11  
little_93_pickup's Avatar
Registered User
 
Joined: Oct 2010
Posts: 91
Likes: 0
From: Wayne, NJ
i work for a towing company and i've never heard of this.
Reply
Old Jan 14, 2011 | 11:30 AM
  #12  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
I have worked for a transmission shop and can see what happens to a transmission when an SUV is flat towed behind a camper for 1500 miles. Granted I think is was a nissan but.....

I don't see a 20 minute tow across town is gonna hurt anything though as you never see a tow truck driver disconnect a driveshaft to repo a vehicle etc.

Last edited by xxxtreme22r; Jan 14, 2011 at 11:33 AM.
Reply
Old Jan 14, 2011 | 11:37 AM
  #13  
4Crawler's Avatar
Contributing Member
20 Year Member
iTrader: (3)
 
Joined: Jun 2002
Posts: 10,821
Likes: 34
From: SF Bay Area, CA
See 2nd Q&A below:
- http://www.4crawler.com/4x4/TLCA_Tru...ech.05.03.html

I got it straight from Marlin that the input shaft spinning is what moves oil around, so the case should at least be in 2H, trans in N. But best/safest is rear drive shaft removed and/or rear F/F w/ hubs unlocked. And have heard of folks flat towing with shaft in and having no issues but have also heard of things going bang like that.

I know on my FWD VW, that they have a similar situation with the transaxle. If flat towing and trans. in N, you are not circulating oil and they recommend no more than about 50 miles towing like that (front/drive wheels on ground).
Reply
Old Jan 14, 2011 | 11:49 AM
  #14  
stereoguy's Avatar
Thread Starter
Registered User
 
Joined: Sep 2009
Posts: 199
Likes: 9
From: michigan
I don't tow a lot but Ive only towed it to silver lake last year and its about 120 miles each way the rest of the time I use a trailer. So far so good I hope I didn't mess anything up . THANKS a lot for the info I plan to tow this a lot this year and would have screwed my transfer case up!! I cant believe I have never heard of this before .

Last edited by waskillywabbit; Jan 14, 2011 at 12:01 PM. Reason: Language
Reply
Old Jan 14, 2011 | 01:28 PM
  #15  
diablo's Avatar
Registered User
 
Joined: Feb 2010
Posts: 146
Likes: 0
From: Graham,WA.
yOU CAN BUY A DRIVESHAFT DICONNECT, SO AS TO MAKE LESS OF A PAIN IN THE YOU KNOW WHAT
Reply
Old Jan 14, 2011 | 01:40 PM
  #16  
MudHippy's Avatar
Registered User
 
Joined: Jan 2007
Posts: 6,106
Likes: 27
^^ Dude...what's with the yelling? Caps lock off please. Thanks!

Last edited by MudHippy; Aug 19, 2012 at 08:36 AM.
Reply
Old Jan 14, 2011 | 02:03 PM
  #17  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
for $750 I will buy a 10mm socket, a snapon ratchet and a 10mm box end wrench and take off 8 bolts myself. Might be 12mm I forget, but everyone gets the point lol.

http://www.remcotowing.com/remco_drive_shaft_coupling
Reply
Old Jan 14, 2011 | 02:06 PM
  #18  
MudHippy's Avatar
Registered User
 
Joined: Jan 2007
Posts: 6,106
Likes: 27
Point taken. But for the record it's a 14mm.

And the one you want is this one for $429. http://frontrangeoffroadfab.com/nfos...87f97c6a1ab4c0 and http://www.lowrangeoffroad.com/rear-..._store=default

Last edited by MudHippy; Jan 14, 2011 at 02:11 PM.
Reply
Old Jan 14, 2011 | 02:13 PM
  #19  
xxxtreme22r's Avatar
Registered User
 
Joined: Aug 2009
Posts: 13,574
Likes: 72
From: Wilkes-Barre, PA, USA
haha I knew I was gonna get for the correct bolt size. I like that FROR disconnect better than the one I goggled up. With that one I wouldn't have to even get my lazy butt under the truck. LMAO.

Plus that one gives you the option on doing front digs on the fly.

EDIT: I must have given wabbit an idea. lol

https://www.yotatech.com/forums/f109...omatic-227639/

Last edited by xxxtreme22r; Jan 14, 2011 at 02:18 PM.
Reply
Old Jan 14, 2011 | 02:18 PM
  #20  
waskillywabbit's Avatar
Banned
iTrader: (-1)
 
Joined: Jul 2003
Posts: 3
Likes: 20
Originally Posted by xxxtreme22r
for $750 I will buy a 10mm socket, a snapon ratchet and a 10mm box end wrench and take off 8 bolts myself. Might be 12mm I forget, but everyone gets the point lol.

http://www.remcotowing.com/remco_drive_shaft_coupling
I actually have one of these for a 96-02 4WD 4Runner Automatic

Originally Posted by MudHippy
Point taken. But for the record it's a 14mm.

And the one you want is this one for $429. http://frontrangeoffroadfab.com/nfos...87f97c6a1ab4c0 and http://www.lowrangeoffroad.com/rear-..._store=default
Acutally driveshaft bolt heads can be 12mm or 14mm depending on year, but sometimes they are mixed and matched.

:wabbit2:
Reply

Thread Tools
Search this Thread

All times are GMT -8. The time now is 11:56 AM.