broken oil pump drive

[huntcoach]

has anyone seen one of these break? did a pump on 98 6.5 td turned crank backwards and broke the shaft. after much agony found oil pump so worn if you turn it backwards it binds up. is this common? i have 15 of these vehicles i need to know if i should do all the pumps. the motor only has 140,000 on it.

[markrinker]

How was crank turned backwards? Also curious about what type of use your fleet of 15 does.

[huntcoach]

the crank was turned with a rachet, the mechanic said he felt resistance but never thought it was the oil pump binding. i have had this one other time while doing a crank seal,another mechanic turned the crank. it only has to go a quarter of a rev. to bind and break. i'm asking to see if i need to change all the pumps or is it an isolated year/incident i have at least 60 6.5s ranging from 98 to 2002

[john8662]

Sounds very isolated, I've turned engines backwards by hand with no ill effects. I've also never seen the drive up top break, did the shaft become rounded?

[huntcoach]

I have turned these motor backwards for many years. i have a fleet of 365 6.2/6.5/6.5tds i have never seen a oil pump wear like this either i have units with 400,000 miles on them and have the orignal pump what im trying to find out is there a flaw in the pump. no the shaft broke /splintered my fleet is a schoolbus operation oil cxhanged 3000 to 4000 miles we are one of the top maintained fleets in the country. we work on these vehicles every day and have never seen this.

[tom.mcinerney]

Hunt,
Your's is first post to report broken oil pump shaft on this forum in past two years. There are some instances of oil pumps degrading thanks to breaks in the integral pressure relief valve's spring.