GMC under engine covers

[chessie4905]

Anybody using the factory under engine covers on their GMCs?

[richard5933]

We've got all the OEM belly pans on our 4108.

My thought is that they help keep the road debris away from the engine, as well as directing airflow as the engineers intended.

Bill at US Coach commented how rare they are to find.

[Geoff]

When I worked for DDA in the early eighties, we used to get transit buses that had the bottom covers on them.  Most of the mechanics would just toss them in the dumpster, but I used to take the extra time to put them back on.  I don't think they helped with cooling, but they were good to keep trash out.  Without them the engine compartment would act like a vacuum cleaner and pick whole newspapers amongst the other street garbage.

I don't think they do anything for a highway bus, the flaps behind the rear wheels are more important in air flow for the engine compartment.

[dtcerrato]

I agree with Goeff, engine debris was probably their main design criteria. We haven't any belly pans but have managed to sheet metal protect everything behind the duals. The AK road trip made it very evident what sheet metal belly pans could prevent, ESPECIALLY beneath the radiator fan "Without them the engine compartment would act like a vacuum cleaner and pick whole newspapers amongst the other street garbage". including dust, sand, gravel, and rock kicked up by the dual tires - even with full width mud flaps... IMHO I think when our radiator fan failed on the way to the Evansville Rally, and after witnessing the amount of metal sand blasted off the radiator fan blades - the  hundreds of miles traveled on loose gravel roads & highways on that (AK) road trip played a devastating part of that fan failure - numerous cracks & fractures on all blade arms besides the one that failed. Rant over...

[luvrbus]

I notice the Prevost entertainer guys are running air filters like for a home in front of the radiator and CCA to try and save the radiator and cooler from the sand and salt in the winter time.Good idea but probably not for a older bus with the 2 stroke   

[Gary Hatt - Publisher BCM]

My Toyota 4-Runner came with skid plates.  Took extra work to change the oil, but I always put them back on.  Taking a few extra minutes to remove and reinstalling them on a bus may save you a very expensive engine.  However if you are running a bus 24/7, and changing the oil very frequently, it may not be worth while. 

I heard recently that Greyhound never changed their oil, only the filters, but they took regular oil samples and if anything looked bad, then they changed out engines.  Not sure how true this is.  But as Abraham Lincoln said, you can never trust what you read on the internet :-)

I usually change my oil in my Series 60 every 500 miles just be safe. Thinking of going to the drip system. :-)

[Templar52]

I have the 3 of them. Very important for keeping the engine comp. clean and safe. We had a fleet of 1700 busses and they were all equiped with dust pans. Imagin a roling bush who roll under the bus and get struck inside the engine comp. . Could go into fire if the debris touch the exaust manifold.

[lostagain]

Mine are off. Helps with cooling.

JC

[luvrbus]

I never saw belly pans on a T drive bus before they be immune against a burning bush,give me break here guys I can sorta see belly pans useful on a GM with the engine cross ways laying on the side and turning the wrong direction but for fire prevention ?   

[dtcerrato]

In the 50s & 60s I learned (then) through old timers in the bus bussiness that Pacific Greyhound never changed oil. Our bus ran two round trips per 24 hour period for 20 years between LA & SF. When the bus rolled into the depot (sometimes inside) as the passengers & luggage was unloading & loading the engine ( never being shut down) was connected to a device referred to as a bus engine dialysis. It took engine oil sample and filtered out what was detrimental and added what was needed. I think that procedure may have been connected to the fact that in Greyhound maintainance  literature it (rarely) stated  they can get oil change intervals as long as over 100,000 miles. The mention of radiator filters - our rad collected many pounds of debris that was coming up from the road between the rad exterior & expanded metal door. We sheet metaled that area closed - anxious to see what (if anything) will accumulate now.

[luvrbus]

In the 50s & 60s I learned (then) through old timers in the bus bussiness that Pacific Greyhound never changed oil.

That had to be a west coast thing I have a stack of maintenance records from the Dallas garage from the late 50's to the late 60's that shows the oil on the GM's and MCI 5A was changed between 12 and 15 thousand miles and Greyhound in Dallas used the Gulf Lube brand of oil I guess because Gulf was big in Texas

[lostagain]

"Never change oil". Sounds like a myth to me... Hey, but maybe that would be a good thing: we wouldn't have to argue about what kind of oil to use...

JC