Jump to content

Recommended Posts

We sold our 1985 Mack Mh to some cousins a couple years ago, didn't think I'd miss it but look where Im at now. Anyways I was thinking of trying to get it back from them someday and fix it up a bit. But it's got some problems that I hope I can learn how to remedy here, here are some I remember: 

1. I was jerky when it was unloaded and it almost seemed like it was starving for fuel but once you got a load on it it was fine. Governor maybe??

2. Leaky rear wheel seals.

3. Motor (e6) might need to be rebuilt.

4. Stop engine light sometimes came on even If all the gauges were fine.

5. foot brake wouldn't pop back up

and probably more but I can't think of them right now. I just thought Id compile some info before putting any money into this project. Any literature would help too! Im not in any big hurry I just really like talking and learning about these old Macks. ill try and find some photos of it and post em here whenever I can. Thanks

Link to comment
Share on other sites

Here's the first picture I found. Another thing I remember about it was that it had a bad leak in one of the rear bags with the air ride. Are these bag's specific to Mack or are they a common part? We've replaced some on a sprayer a couple of times, not that big of a deal once you have it jacked up right. 

F46CAAE9-BEA8-4D3F-8804-1301CD45816F_4_5005_c.jpeg

  • Like 1
Link to comment
Share on other sites

BOB

#2  when you replace the seals, and probably the brake shoes, Check the wheel bearings close!! Worn bearings will be loose and cause seal problems..

#5  Clean out the dirt behind the pedal then soak it good with penetrating solvent, work it, and repeat several times..

 

  • Like 2

Brocky

Link to comment
Share on other sites

If The engine is not smoking or making weird noises and you have a good oil pressure I wouldn’t worry about a rebuild unless you’ve got high mileage you could drop the pan and put a set of rods and main bearings in it sometimes are you have to do is adjust the valves and that will make a big difference if it’s running rough .. bob

  • Like 1
Link to comment
Share on other sites

1 hour ago, mowerman said:

If The engine is not smoking or making weird noises and you have a good oil pressure I wouldn’t worry about a rebuild unless you’ve got high mileage you could drop the pan and put a set of rods and main bearings in it sometimes are you have to do is adjust the valves and that will make a big difference if it’s running rough .. bob

It ran and pulled pretty good when we had it besides the the no load jerkiness. The pump might need to be looked at but it's just a Bosh pump that was in everything in the 80s right? And what's the best way to get parts for these old Macks? since I don't think Volvo's still supplying parts. 

Link to comment
Share on other sites

i would think there will be a few items to consider ; 1- what it will cost $$ to buy it back;2- how many miles on it;3- how many miles do you plan on putting on it?4- has it been parked for yrs ? buy back for memories or to run. might be the jerkiness is from sticking fuel linkage ( they do have fuel linkage on those new trucks or maybe all electronic ). definatly soak the brake pedal alot. have seen many that use a punch and hammer , next thing you know the alum ears on the mount are broke.

Link to comment
Share on other sites

1. We sold it for $1000 so buying it back might not be the issue (unless my uncles have gotten real attached to it). The money is really going to go into parts.

2. I never remember the speedometer working so I'd guess maybe a half a million? I never looked down at it 

3&4. It's a farm truck but I might do some 100+ mile grain trips with it.

I don't think the jerkiness is from sticky linkages because It doesn't happen under load, Air rated fuel maybe?? and I can get the brake petal off no problem but it's the actuator that you can push down put it won't pop back up. Ive worked on It for days with no luck before. 

Edited by BOBWhite
Link to comment
Share on other sites

58 minutes ago, BOBWhite said:

1. We sold it for $1000 so buying it back might not be the issue (unless my uncles have gotten real attached to it). The money is really going to go into parts.

2. I never remember the speedometer working so I'd guess maybe a half a million? I never looked down at it 

3&4. It's a farm truck but I might do some 100+ mile grain trips with it.

I don't think the jerkiness is from sticky linkages because It doesn't happen under load, Air rated fuel maybe?? and I can get the brake petal off no problem but it's the actuator that you can push down put it won't pop back up. Ive worked on It for days with no luck before. 

What one man might define as "jerky" another might describe as a lull in the idle. Low speed governor springs could be worn out. But I've never messed with a fuel pump other than adjusting timing or idle speed.  If your heel isn't planted on the floor while you're driving around it'll be a jerky ride...

Link to comment
Share on other sites

3 hours ago, JoeH said:

What one man might define as "jerky" another might describe as a lull in the idle. Low speed governor springs could be worn out. But I've never messed with a fuel pump other than adjusting timing or idle speed.  If your heel isn't planted on the floor while you're driving around it'll be a jerky ride...

Yeah that was my first guess was a governor issue. But the jerkiness is like a random misfire, I wouldn't think it would be a fuel supply issue because it goes away when you have a heavy load on it. Also do all Mack transmissions use the same bolt pattern? Because I think it had a mack t2090 and it's ok but it shifts kinda rough and top gear was always hard to get into. I want to put a t-2180 into it instead of putting money into that 9 speed. 

Link to comment
Share on other sites

Sorry that was supposed to go in the super liner tread… but getting back to the MH possibly U joints???? But I’m sure you know what you’re talking about and it’s definitely engine issues.. Bob

Link to comment
Share on other sites

Another question I had: What did the shifter look like in the 18 speed Mh cabovers? More specifically where did the Hi-Lo selector move too? Thanks676AED84-06F6-4A71-BF4D-BF07A402B0C1.thumb.jpeg.0f080787602762766cc5a9733eab122b.jpeg

This is what ours looked like and I don't see a good place to put the splitter if I swap an 18 speed In it.

Link to comment
Share on other sites

I’m sure it’s right at the top instead of the side that’s the way all the newer shit is you could probably just change the shifter ball that’s probably the least of your troubles ha ha good luck nice clean interior by the way .Bob

Link to comment
Share on other sites

1 hour ago, mowerman said:

I’m sure it’s right at the top instead of the side that’s the way all the newer shit is you could probably just change the shifter ball that’s probably the least of your troubles ha ha good luck nice clean interior by the way .Bob

Yeah Im sure there's going to be something else but looking at both transmissions side by side they look like they have the same 11 bolt pattern. And there's probably nothing wrong with my 9 speed the shift linkage probably just needs adjusted. Oh and I wish this was my interior! I ripped this straight out of the catalog

  • Like 1
Link to comment
Share on other sites

i kind of have the same doubts .....i bought a quadbox out of a B model 25 years ago for my DM,,,it was all rebuilt 350 bucks its still sitting on a pallet behind my house and i still dont know if its going to bolt up,,,,reminds me of old jonny cash tune,,went to put the bolts in,and all the holes were gone...lol.bob

Edited by mowerman
missing word
Link to comment
Share on other sites

Im collecting digital literature on Mack Mh's and I was wondering if anyone has an owner/operators manual for one. I saw there was one on this wiki once but I think Volvo put a stop to that. Also any brochures for them are really cool to look at if anyone has any. Thanks!

Link to comment
Share on other sites

I dont know if this will help you, but I buy manuals from a website called:  "My power manuals.com" (one word) I have about 12. all are engine books..  instant downloads, low prices, and I put them on 2 C.D''s and load them onto a laptop that is in my shop, then put the C.D.'s in a case in my office, in case I need them again..  good luck, jojo

  • Like 1
Link to comment
Share on other sites

thanks man I checked them out but $40 for my engine manuals a bit much for me. I mean if I used it everyday it would be invaluable but I'm a novice so I won't use it that much. Im mainly looking out for downloadable pdf's that are cheep or free.

Link to comment
Share on other sites

ok.. gotcha..  well if I have any info you need in my books, I can take pics and send it through P.M. or text... jojo

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...