Ok so i put a post up a week or 2 ago about my 4wd acting up ... When ever i run my truck in 4wd whether its on bare pavement or snowy roads it always vibrates and makes a consistent rattling noise which sounds more so in the transfer case ive kept my hubs unlocked and truck in 4wd and it makes the rattling noise and vibrates so Im assuming its an issue with the tcase but l also kept the truck in 2wd and locked the hubs and it still makes the noise ... IM STUMPED !!! ... I did a solid 4.10 ratio front axle swap out of an 83 f350 and i was suggested to make sure that the axle ratios are the same ... My axle code is 4N which is a 4.10 LS and the solid axle i put in is a 4.10 also ... Apparently theres 2 different kinds of ratios like 4.10 and 4.10 LS ... What the hell does the LS stand for ?!?! I need this truck for the spring and summer to use on the farm and just offroading in general so i NEED to figure out whats wrong and fix it ... Any suggestions on my 4wd problems or any advice would be great !!! THANKS !!!

 

Ls is limited slip and it doesn't matter if your hubs are unlocked and the tcase is locked the front axle will still spin and vice versa look at all your ujoints on the front shaft and axle shafts

 

Is your truck lifted? Did you swap to the F350 front drive shaft with the double cardan joint? I suspect the vibration is due to drive line misalignment.

 

I have the drive shaft from the solid axle but im not sure if its different ... If it is the double joint would it bolt right to my transfer case for my 351w

 

Pull the front drive shaft & test again. If it only vibrates with the T-case in 4wd, it's in the T-case. If it only vibrates with the hubs locked, it's in the axle. If it doesn't vibrate either way, it's the drive shaft...

 

It would IF you changed the yoke on the t-case at the same time.

This is a F350 front shaft and is a MUST for a lifted truck.



This is a F250 front shaft. Sometimes you can get by with using it on a stock height F350, but the length will need to be changed.

 

I have a Borg Warner 4407 tcase that I plan on working to put in my truck and it came out of an f350 I believe so maybe the front shaft will work perfectly and the drive shaft like has been said needs to be worked but my father in law is a welder/fabricator so it shouldn't be a problem

 

you need to get a new/modified driveshaft balanced if you plan on driving anywhere besides a field.


also, as for your original post it sounds like u joints are bad either in the driveshaft or the axle(s). granted, it could be one (or more) of a few things, but all else aside that is the greatest possibility of cause.

 

Why a new thread, nothing has changed.
For other readers here is a link to the previous thread. https://www.ford-trucks.com/forums/1...-problems.html




[QUOTE=Gear619;15115279
... I did a solid 4.10 ratio front axle swap out of an 83 f350 and i was suggested to make sure that the axle ratios are the same ... My axle code is 4N which is a 4.10 LS and the solid axle i put in is a 4.10 also ... Apparently theres 2 different kinds of ratios like 4.10 and 4.10 LS ... What the hell does the LS stand for ?!?!
[/QUOTE]
LS = Limited Slip


It was also suggested that you not go by tags or codes, you need to actually count. Though not likely the issue.


Your donor axle couldn't be from a 83, 83 F350s didn't have D60s.


You need to mention again that your truck is lifted 6" also.