1965 Posted October 8, 2016 Share Posted October 8, 2016 Leased on with a guy's company; he has a 12 model Volvo that the bull gear bearing retainer backed off; I have a 12 model Chu & wondering how I would know if my truck falls under this same problem; & what I should do Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/ Share on other sites More sharing options...
Macktech689 Posted October 8, 2016 Share Posted October 8, 2016 Double idler gear failures are not uncommon. Starting in 2010 the oil temperature was raised to 238 degrees and the hotter oil was causing the retainers to loosen, originally the retainers were installed with Loctite and not staked in place. After a rash of failures staking the retainers was put into production can't remember exactly when. There was a campaign to "pin" the retainers for a while, haven't done it in years, You could ask your dealer about it and see if they would be willing to do it for you. It's possible the gear in your engine has a staked retainer already. Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-348168 Share on other sites More sharing options...
1965 Posted October 8, 2016 Author Share Posted October 8, 2016 My dealer not going to do anything for me wonder if VIN # could tell anything? Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-348171 Share on other sites More sharing options...
Macktech689 Posted October 8, 2016 Share Posted October 8, 2016 I can't help with the VIN, the pinning campaign was PI0785 and was issued in May 2102. You can check your trucks build date it's on the decal inside the drivers door jamb, you could also contact Mack to see if your truck was part of this campaign and whether it was already done. Another thing to look at is to see if a plug is installed in the top of the flywheel housing next to the crank sensor, the plug is put in after the pinning is done. Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-348172 Share on other sites More sharing options...
1965 Posted October 8, 2016 Author Share Posted October 8, 2016 Built 09/2011 I'll check with Mack & see what I can find out; also check for the plug thanks for input Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-348173 Share on other sites More sharing options...
fjh Posted October 9, 2016 Share Posted October 9, 2016 (edited) It would be good to check with them we have had a couple of these slip thru the pin campian cracks it happens on MP ten as well, ( No campaign on these) if you have a clattering sound coming from your engine or your compressor comes loose you better ask why! or you may be out 20-30 grand. depending how catastrophic ! Edited October 9, 2016 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-348259 Share on other sites More sharing options...
1965 Posted December 14, 2016 Author Share Posted December 14, 2016 On October 8, 2016 at 1:05 PM, Macktech689 said: I can't help with the VIN, the pinning campaign was PI0785 and was issued in May 2102. You can check your trucks build date it's on the decal inside the drivers door jamb, you could also contact Mack to see if your truck was part of this campaign and whether it was already done. Another thing to look at is to see if a plug is installed in the top of the flywheel housing next to the crank sensor, the plug is put in after the pinning is done. My truck was built in 11; looking at flywheel housing there's no plug; I've watched the u-tube video & my flywheel housing doesn't look exactly like 1 in video; the line they tell you to remove is in different spot; just wondering if this maybe a tell tell sign of updated engine; having to r&r clutch & was going to pull flywheel housing off to check bullgear; but didn't want too if it had updated gear; research with Mack has been no help; also was wondering if you could see with camera from top or bottom thanks for any help in this matter Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-355090 Share on other sites More sharing options...
Macktech689 Posted December 15, 2016 Share Posted December 15, 2016 There was no change to the flywheel housing when the staked idler gears were installed, removing the housing is no small job the back and bottom of the engine needs to come off. You can check the idler gear through the PTO cover at the top of the housing on the right side to see if it is loose, if it is you will also see where it's rubbing on the housing. The video you mentioned may have been of a MP-7. A good picture of the top of the housing would be helpful, a pic of the bottom won't show anything. Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-355192 Share on other sites More sharing options...
1965 Posted December 15, 2016 Author Share Posted December 15, 2016 2 minutes ago, Macktech689 said: There was no change to the flywheel housing when the staked idler gears were installed, removing the housing is no small job the back and bottom of the engine needs to come off. You can check the idler gear through the PTO cover at the top of the housing on the right side to see if it is loose, if it is you will also see where it's rubbing on the housing. The video you mentioned may have been of a MP-7. A good picture of the top of the housing would be helpful, a pic of the bottom won't show anything. Pulled flywheel housing off; nut seems to be tight; just going to stake it up; not much meat there to stake; everything looks good; can't find socket to check torque but can see the loctite & looks as nut hasn't moved any suggestions Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-355193 Share on other sites More sharing options...
fjh Posted December 16, 2016 Share Posted December 16, 2016 Drill it and drive a roll pin in! make sure your not to close one of the nut drive lugs when you drill and it will be fine.close it back up 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47181-bull-gear-on-mp8-engines/#findComment-355257 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.