Help with 1986 B150 Van

From : preacherman

Q: i have a 1986 dodge van b 150 1/2 ton 318 engine auto trans 8.25 rear axle. i am in hope you all can help me figure out a problem that has me very stumped. first i will list the symptoms and then what has been already changed/repaired. it started with turning to the right from a dead stop i could feel a grinding sensation from the rear .... along with a thud when breaking .... when coming to a stop and not letting off the brake till i could go ... once off the brake and moving forward i would hear/feel a thud from the back end almost like being bumped in the back end. it also will do this at speeds of 10mph at times but not while changing gears. it feels like a slam in the back. also upon heavy acceleration forward the grinding is there ... not just to the right anymore. now here is what has been done. both sets ujoints changed spider gears replaced trans mount checked brakes checked for grease on shoes after changing the spider gears it has helped .... but upon heavy acceleration it still has a grinding feeling ... and i still have the thud ... the rear gears all looked good the spiders were worn so changing them out was well worth it .... what am i missing here where could the thud and the left over graind be coming from thanks in advance for the help and ideas!! dave .

Replies:

From : budd cochran mrd150 preciscom spam net

check for slop in the pinion shaft and your outer axle bearings. i have a feeling not much fluid drained out of the rear axle when you r&rd the spider gears. is it a limited slip sure-grip differential -- budd cochran romans 323 romans 623 john 316-17 ephesians 28-9 i have a 1986 dodge van b 150 1/2 ton 318 engine auto trans 8.25 rear axle. i am in hope you all can help me figure out a problem that has me very stumped. first i will list the symptoms and then what has been already changed/repaired. it started with turning to the right from a dead stop i could feel a grinding sensation from the rear .... along with a thud when breaking ... when coming to a stop and not letting off the brake till i could go .. once off the brake and moving forward i would hear/feel a thud from the back end almost like being bumped in the back end. it also will do this at speeds of 10mph at times but not while changing gears. it feels like a slam in the back. also upon heavy acceleration forward the grinding is there ... not just to the right anymore. now here is what has been done. both sets ujoints changed spider gears replaced trans mount checked brakes checked for grease on shoes after changing the spider gears it has helped .... but upon heavy acceleration it still has a grinding feeling ... and i still have the thud ... the rear gears all looked good the spiders were worn so changing them out was well worth it .... what am i missing here where could the thud and the left over graind be coming from thanks in advance for the help and ideas!! dave .

From : preacherman

hi budd - did check slop in pinion and it seemed normal .... outer bearings as well with no wear to the axle shafts .... fluid was normal as it had no leaks and always checked in service ... it is an open carrier no clutch pack ... any ideas ... also i did forget one other symptom -- at 35 -45 i get a vibration at times and other times not at all ... something really strange is going on and i just cant figure it out to save my life . .

From : budd cochran mrd150 preciscom spam net

as far as you know considering the van may have been purchased used has it ever been high centered which might bend and bind the driveshaft. a hardly noticeable bend could cause these symptoms. another possibility is loose backing plates on the rear brakes. were starting to run out of the more common causes quickly ^/ -- budd cochran romans 323 romans 623 john 316-17 ephesians 28-9 hi budd - did check slop in pinion and it seemed normal .... outer bearings as well with no wear to the axle shafts .... fluid was normal as it had no leaks and always checked in service ... it is an open carrier no clutch pack ... any ideas ... also i did forget one other symptom -- at 35 -45 i get a vibration at times and other times not at all ... something really strange is going on and i just cant figure it out to save my life . .