Re: [SyncroDoubleCabs] Syncro 16 Doka overloading caused driveshaft vibration

On 8/11/08, David Marshall <> wrote:
Can't see load making a drive shaft change angle - the engine / gearbox and the front differential are fixed in position and there is no real way for the driveshaft's universal joints to change in angle enough to get out of phase - that would take quite a bit to become as severe as you are suggesting.  My guess is that your CVs are bad.  As they change angle the balls ride on a different location in the cage.  The balls now with no load are riding on  location that arn't worn.

David Marshall
I will look into the CV's. As others have mentioned via pmail, the engine and gearbox might be designed to be in a fixed position relative to the engine but there can be some deflection due to worn mounts. The engine mounts are new but the transmission mount and front differential mount are not.

On 8/11/08, Eric D <> wrote:

I have to take Davids side on this one…  It just seems a bit retarded that you can't throw weight into a 16",

a model that was specially designed to handle more weight than a standard 14". 

Don't let the facts confuse you. =)   Syncro 16's may have heavier duty equipment but IIRC their carrying capacity is NOT better than "standard 14" Syncros. They are all half ton trucks.

 I would suggest that you drove a driveshaft that sat for an extended period, driving it some more may have

freed it up.  Like David mentioned, the transaxle, driveshaft and front diff are in fixed relationships.

In fact the truck was being driven daily of late though not for extended periods or high speeds. As I mentioned in my response to David, I will recheck the CV's. They were inspected and repacked by a well-respected Syncro specialist some time ago. There hasn't been a lot of miles since that inspection. There was no worn spots noted at that time. However, I will not discount anything at this point and check for myself.
Later on, I plan on putting a similar weight in the cargo bed to replicate the load conditions under which the vibration occurred. The truck is specifically being driven for longer periods at higher speeds (hahaha -- it's just an AAZ) before reloading. The intent is to eliminate speculation about the lack of use for extended periods as being one of the causes.