Drive axel touches frame? Help!!

I'm just throwing darts at this, but while you're spraying down stuff looking for leaks, make sure the slip joint/yoke whatever its called isnt siezed. Dump and inflate the bags a few times and see that it is moving freely. I know of a handful of volvos that had driveline issues from siezed slip shaft. I dont know that any of them had contact with cross members though.. I just know that I have previously spent 10k (and learned, since) chasing a vibration and fixing symptoms rather than the getting to the ROOT..... Something that ended up being as stupid as loose U bolts.

All I'm saying is, leave no stone unturned. Especially simple ones! I dont know much about driveline and suspensions stuff, but if its stiff, perhaps it could cause the front drive axle to "load up" differently than the rear, throwing your driveline angles and suspension load way out of whack? Or not at all and I'm talking out of my ###. Just throwing it out there, good luck!

 

Good pre-emission combo.
Volvo did not use Detroits since 2001 i believe, the 07s came with Cummins, or Volvo D12 / D16 , I wonder if this customized engine swap required some changes in driveline.

 

Leveling valve is probably bad, air govenor should be set at 125 to keep enough pressure in air bags when loaded heavy so the valve can do it’s job. Regardless you’d think with air dumped the stops would hold it above the point of hitting cross member. I think the leveling valve is just bad and not set high enough. Maybe stops are just bad design. Higher stops might bottom out even When leveling valve is set right. Should be able to figure that out, once air ride is set up right. I think a new valve set high enough will fix the problem. Just an opinion.

 

@newdriver2
1° problem.............the driveshaft.
Possible causes:

-wrong crossmember(you said it was original so that is not it)

-stopblocks no pictures yet off them,you have not checked with Volvo how high they should be so they are still a open question.

-driveshaft you say it has been replaced so it could be a bigger one then the original one.Only solution is measuring it and checking with Volvo.

-failing bearing on the input shaft off the drive axle unlikely but very easy to check.Get under the driveshaft and lift it.You will feel it is there is play or not.

-Drive axle highly unlikely but in theory it could be that someone put a smaller diameter drive axle thus screwing up the distance between the driveshaft and the crossmember.(i don't think that happend)

-springs for bend springs to influence the driveshaft the front part off the springs would have to be bend.The pictures show that the drive is flat and not twisted upwards so highly unlikely.

Too those who talk about tires being the cause...............sorry but you are wrong.
Tires have no influence on the driveshaft vs crossmember distance.

 

@newdriver2
2° problem.............the airbags.

you said that with heavy loads the driveshaft touches the crossmember when loaded heavy.
That hints at airbags not getting enough air in time.
Basicly your truck is bottoming out with heavier loads.
That is not normal.
And the only way to really check that is measuring.
Hence my previous post to put gauges.
It could be that not all 4 airbags are getting the same pressure or it could be that all 4 are just getting low pressure.
There are different ways to measure that.
@Johny41 's idea is good or you could put 4 simple cheap gauges.
For that you are best to go to a local supplier and see what you can buy without breaking the bank.
Those gauges can also very good for you to see how heavy your are on your drives thus knowing if you are legal or not so they have a future use.

 

@newdriver2
Do you dropp off the can with the chassis in a parking lot or does the can get lifted off your truck by the terminal crane?

 

This is the amount of space my 780 has over the u-joint.



Make sure the bump stops are still in place on the outer edge of each axle tube. They are bolted to the outside of the frame rail with three bolts. There are four of them... just a piece of stamped metal about a quarter inch thick.

 

By the way... the u-joint pic is with my bags dropped, axle tubes touching the bump stops.