Only time I have seen this happen was due to the thrust bearing put in backwards. I actually did it about 10 years ago and killed the crank and block. Also depending on what clutch you run--thats hard on them also.

 

x2 on what Crash said. PO to my truck put the thrust washers in backwards. Lasted long enough for me to put about 1000 miles on the truck before one fell out and the crank started walking back and forth. Nuked the block, crank and a few conn rods. Did you check the spec's on the clearances when you rebuilt it? They make a few different sized thrust washers.

 

If they put any kind of warranty on their work, take it back and have them buy you a new motor if anything got damaged, or have them build it again for free. Thats F'd up

 

well...the problem is they are an absolute shit company. i cant just pull the motor out with the quickness. it took me a little while to get the truck back together after i got the motor back from them. and by the time i had the block pulled they went back on their word about fixing it. i know better now, ill call up thunderbolt out of houston and have a motor the next day...


i was thinking that the thrust bearings where put in backwards...now i need to find some replacements. i think everything else is fine. i know lc engineering sells some but i dont know what sizes there are.

 

measure what you need and call, lc engineering, or www.engnbldr.com

you can also get thrust bearings pretty much anywhere..... can even order them from the local parts stores also