91 Land Cruiser won’t drive unless CDL is engaged

[Youngypsy]

Hey everyone!

Now that my cruiser finally runs I’ve been slowing getting it road ready as this car originated from a scrap yard so a lot of TLC has been needed and numerous parts to be added back

This is a 91 LC with the 3FE & auto trans with center diff only (US model)

Some things to note is the only two things missing drivetrain wise were the CDL button, and the front drive shaft
(Both removed from PO)
Fluid clean and at the correct level on the dipstick

Today I decided I was gonna just cruise it around the block to see if how it would drive in its current state. Fired up the truck and when I went to put into Drive and let off the brake nothing. There was a slight RPM change but when I moved the gear selector into reverse, 3,2,and 1 I still had still zero movement in the truck. Decided I was gonna do a quick check underneath and when I went to put the truck in park I got this bad grinding noise and I couldn’t put it in park so I turned off the truck in neutral and then i was able to put it back in park no issues. I looked under the vehicle and couldn’t see anything glaring that could be wrong so I thought maybe I’ll try to drive it with the CDL on. Started the truck again and this time before going into gear I engaged the CDL I put the T case into H and behold the truck drove! Every gear option worked and the truck drove perfect but of course turning was not ideal. Same scenario when the T case was in L.

Thought I might have been over looking something so I went digging on here and did some troubleshooting.

Had my buddy put the car in drive with the CDL off and there is no movement from either driveshaft, same as well for all other options. Have yet to pull off axle covers, will be doing that tomorrow!

Any other checks advised??

Thanks in advanced! Always appreciate the help from the MUD community

 

[Rusty Marlin]

Story confusing, does it have a front drive shaft now or not?

 

[Broski]

If there’s no front drive shaft then that the problem.
If both drive shafts are present then make sure the transfer case is engaged.

 

[Fj80oregon]

Stripped drive flanges up front maybe? I’m assuming you have the front driveshaft because you said no movement on either driveshaft.

 

[Squash]

Pull the caps, then observe as someone put her in high and gear, your CV is probably spinning because one of the two sides are stripped.
Note; The thickness of driveplates and length of CV...these should match and are interchangeable.

 

[jonheld]

Hey everyone!

the only two things missing drivetrain wise were the CDL button, and the front drive shaft

This vehicle is fulltime 4WD with a locking center differential in the transfer case.
In the OEM configuration, the center differential can be locked in high range by pushing the dash switch (standard in 91/92 FJ80s), or by shifting the transfer case into low range, which automatically locks the center differential.

If there is a drive shaft missing there will be no movement as the differential in the transfer case is open. All power will be transferred to the missing drive shaft side of the transfer case because it's an open differential.

If both drive shafts are installed and there is a stripped drive flange on one of the front hubs, there will be no movement as all power will be transferred to the open in the driveline because all differentials are open.

With any missing or failed driveline component, the vehicle can only move once the center differential is locked. Once locked, power is now distributed equally to both front and rear drivelines.

 

[Broski]

Stripped drive flanges up front maybe? I’m assuming you have the front driveshaft because you said no movement on either driveshaft.

If both drive shafts are not moving then it's not a drive flange.

 

[calokie]

if both drive shafts are installed and no DL movement ...Viscous Coupler?

 

[jonheld]

if both drive shafts are installed and no DL movement ...Viscous Coupler?

No VC in the 91/92 HF2A transfer case.

 

[calokie]

No VC in the 91/92 HF2A transfer case.

ah yes, this i had forgot

 

[Youngypsy]

Alright so I’ve got an update to close this thread out

Turns out My LC runs and drives perfect! Due to my due diligence and being a total noob with this platform I’ve come to realization that the reason my truck wasn’t “moving” was as due to the fact that the T case was in neutral. Due to it being in neutral of course it doesn’t move when you put it into gear because it’s all-time AWD and the T case must be engaged to drive.

Although I feel like a dork for even posting I’d still like to thank all the members for coming with knowledge to help! Ultimately I did find that my driver side axle is leaking pretty good so not a complete waste of time lol

 

[Rusty Marlin]

Thank you for the update!
Glad to hear it was nothing more serious than the loose nut behind the wheel.

 

[cahill]

Alright so I’ve got an update to close this thread out

Turns out My LC runs and drives perfect! Due to my due diligence and being a total noob with this platform I’ve come to realization that the reason my truck wasn’t “moving” was as due to the fact that the T case was in neutral. Due to it being in neutral of course it doesn’t move when you put it into gear because it’s all-time AWD and the T case must be engaged to drive.

If your transfer case was in neutral, how was it able to drive with the CDL locked? Am I missing something?

 

[Broski]

Alright so I’ve got an update to close this thread out

Turns out My LC runs and drives perfect! Due to my due diligence and being a total noob with this platform I’ve come to realization that the reason my truck wasn’t “moving” was as due to the fact that the T case was in neutral. Due to it being in neutral of course it doesn’t move when you put it into gear because it’s all-time AWD and the T case must be engaged to drive.

Although I feel like a dork for even posting I’d still like to thank all the members for coming with knowledge to help! Ultimately I did find that my driver side axle is leaking pretty good so not a complete waste of time lol

Post # 3 for the win