03' Big Red Posted April 29, 2023 Share Posted April 29, 2023 I have two R models a 98 & 03 Both have oil leaks at the back of the engine AFTER the transmission has been out, rear structure resurfaced, new rear main seal and oil pans resealed. Any insight to what the problem may be? Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/ Share on other sites More sharing options...
880joe Posted April 29, 2023 Share Posted April 29, 2023 Possibly the rear cam plug 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530356 Share on other sites More sharing options...
JoeH Posted April 29, 2023 Share Posted April 29, 2023 If it's an auto then you probably have cracked flywheel housings. Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530426 Share on other sites More sharing options...
03' Big Red Posted April 30, 2023 Author Share Posted April 30, 2023 On 4/29/2023 at 11:00 AM, 880joe said: Possibly the rear cam plug I’ll look into that Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530527 Share on other sites More sharing options...
03' Big Red Posted April 30, 2023 Author Share Posted April 30, 2023 22 hours ago, JoeH said: If it's an auto then you probably have cracked flywheel housings. It is a automatic in the 98 Flywheel housings on both trucks went to machine shop to be squared up. not sure about cracks Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530528 Share on other sites More sharing options...
JoeH Posted April 30, 2023 Share Posted April 30, 2023 Look along the flywheel housing from the starter motor, up over the top to about a 2:00 position. Mack dealer couldn't get one, but I found one aftermarket at a warehouse in Allentown PA, picked it up.about an hour after talking to the guy. I think it was about half the price Mack wanted for it. Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530530 Share on other sites More sharing options...
JoeH Posted April 30, 2023 Share Posted April 30, 2023 If it's cracked then call your Mack dealer and get the part number for the housing, there's a lot of aftermarket supply for them, you just need to Google the part number and pick a supplier. It's a common failure, and there's a lot of auto garbage trucks demanding them. Note the aftermarket part number will be a close match but will be missing one digit. And your old bell housing to flywheel housing bolts likely won't fit, I think the original is metric and the aftermarket is SAE. Or other way around. Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530531 Share on other sites More sharing options...
Joey Mack Posted April 30, 2023 Share Posted April 30, 2023 JoeH has good point as well as 880 Joe, and This Joe, asks,,, when you put the flywheel housing on did you put a generous bead of MACK GRAY RTV, around the mounting surface on the block and cam plug seam? Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-530534 Share on other sites More sharing options...
JoeH Posted May 12, 2023 Share Posted May 12, 2023 On 4/29/2023 at 9:56 AM, 03' Big Red said: I have two R models a 98 & 03 Both have oil leaks at the back of the engine AFTER the transmission has been out, rear structure resurfaced, new rear main seal and oil pans resealed. Any insight to what the problem may be? Ever find the leak? Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-531282 Share on other sites More sharing options...
03' Big Red Posted January 29 Author Share Posted January 29 On the 2003 the cause of “oil leak” was actually a over zealous national oil change shop that pumped way to muc grease into the throw out bearing the 98 was leaking at air compressor, oil filter mount and looks like the rear main seal was damaged when it was installed 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-545790 Share on other sites More sharing options...
Solution 03' Big Red Posted April 5 Author Solution Share Posted April 5 On 4/29/2023 at 9:56 AM, 03' Big Red said: I have two R models a 98 & 03 Both have oil leaks at the back of the engine AFTER the transmission has been out, rear structure resurfaced, new rear main seal and oil pans resealed. Any insight to what the problem may be? The 98 was a cracked valve cover, pin hole in oil pan and rear main seal that was installed improperly Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-549425 Share on other sites More sharing options...
terry Posted April 5 Share Posted April 5 Thanks for the update. terry Quote Link to comment https://www.bigmacktrucks.com/topic/72800-oil-leaks/#findComment-549426 Share on other sites More sharing options...
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