New Guy - Just drove my '59 B61 from Austin/TX to Seattle/WA, questions

[76cmc]

A little history and a few questions.

I've had my '59 B61 for 5 years or so and it was restored by the guy I bought it from. It was originally a tractor but they mounted a Stainless Steel Fruehauf box with lift gate to it. The lift gate makes this truck extremely handy, and also has foot controls so you can control the deck while steadying your load. I think the engine/trans are from a '60's R as it's a turbocharged diesel mated to a 5 speed.

I moved to the Seattle area in May and just flew back to drive the Mack up. I'm retired and my hobby is vintage cars/trucks. I filled the Mack up with my shop tools/parts etc.... I don't have a CDL so I titled the Mack at 24900 GVWR so I could stay under the WA 25K gvwr requirement. The first weigh station I stopped at showed me at 23400 loaded, so that was close.

The Mack had always run good for the years I had it, but I had a full service to include all new tires before I left. Nothing major was found, just fluid/filter changes and a minor radiator repair.

I drove straight west on I10 from Austin to LA and then North on I5 to Seattle. There are less mountains etc... this direction then a straight diagonal and I wanted to take it easy on the Mack. It was 2500 miles and only about 300 miles extra then the more direct route so worth it for me.

Mack Performance on the drive

1. Overall great!

2. Speed: Top speed is ~65mph on the flats. Low speed was 40-45 on the climbs.

3. Temp: Average ~180, Low ~ 150 in cool mornings or cruising down a 6%, High 228 climbing up a steep grade around LA and one spot in the Shastas.

4. Oil Pressure: 40-50 range

Issues/Questions

1. Transmission jam - my only real problem is that the trans jammed on me twice. I was able to unjam it the first time, but the second time I had to call a guy. If I came to a stop in first on an incline and allowed the truck weight to rest against the gear before shifting to neutral or applying brakes then I couldn't get it out of first. Very strange, it didn't even seem like the stick moved at all, but internally it moved enough that the trans was no longer in first/neutral. When I let the clutch out, the clutch would burn but the truck wouldn't move. The first time I was able to muscle it out. The second time was worse and I didn't want to put anymore pressure on the stick so I called a guy. I figured I just needed to hook up a strap and have him slightly pull the Mack to get the weight off the trans and the stick would pop out, which it did. He thought there was an issue in the trans at the shifter, worn parts etc.... I'm wondering if it's just a clutch adjustment. If the clutch is fully releasing, shouldn't that take the weight off the trans? or are there some worn parts on the shifter I need to look at?

2. Throttle lock cable - The one that came with the truck didn't work so I had my mechanic friend install a new one. Unfortunately, he didn't get the brass plug at the end adjusted so it was of no use. Due to slack, the cable would only lock the pedal around 50mph. Therefore, cruise control was my foot for 2500 miles. I tried to adjust on the road, but crawling underneath and trying to reach up to it, no way. I looked at King Cruise for a cruise control but before I left, but didn't do it. Has anyone installed a King Cruise control? Worth it, or just get the throttle lock cable adjusted?

3. Book/Manual - Is there a recommend book/manuals out there for the B61 and engine/trans (along with identification info so I could ID my engine/trans)?

Thanks for any info/advice!

[farmer52]

Welcome to BMT. I can't answer your first two (2) questions. As for book/manual....send a letter or email to the Mack Museum with the vehicle serial number. They will send you a copy of the original build sheet along with other information. They do this free of charge but a "nice" donation is in order once you see all the information you receive. The backlog is 6-8 weeks. You can get the Museum contact info at the Mack Trucks website.

[j hancock]

Welcome!

The engine model number is stamped on the cast timing chain cover just in front of the injection pump. ENDT675 is a 237 hp. for example.

Can't help with a cruise control system. Clutch may need adjustment and the fork in the trans may be worn out.

Oh yeah, we need some pictures

[Bigdogtrucker]

Sounds like you had a good trip!Any pics?

[76cmc]

I hope this picture was added. I guess to add pictures to a thread, you have to upload to "gallery" and then link to the post via "My media". This is a pic as I just drove on to the Tacoma Narrows bridge. Will add other pic's of the truck later today. Thanks

[Brocky]

Welcome to the doghouse!!! Sounds like you had a great trip.

When you go down to the reply box in the lower right corner is "more reply options" this will ask you to "browse" to your picture library, open your picture and attach and post.

[gearhead204]

if at a stop can you get the truck in gear.... or does it rumble in the stick then jump slightly as it goes into gear? if this is not the case I don't think its clutch related. it may be a twisted mainshaft in the trans. does the clutch have 1 1/2 -2 in. of freeplay at the top of the pedal? does the bottom 1 in. work the clutch brake properly ? I assume that when you had the truck pulled backwards the eng was off. does the trans feel like its right shifting it with the eng. off?

[slpwlker]

It could be clutch related. My Pete when the new clutch was installed wouln't get out of gear sometimes for nothing. had to let the clutch out a bit and get the truck to move and then get it out of gear

[76cmc]

Welcome to BMT. I can't answer your first two (2) questions. As for book/manual....send a letter or email to the Mack Museum with the vehicle serial number. They will send you a copy of the original build sheet along with other information. They do this free of charge but a "nice" donation is in order once you see all the information you receive. The backlog is 6-8 weeks. You can get the Museum contact info at the Mack Trucks website.

I'll do that, sounds like excellent information. Thanks!

[76cmc]

if at a stop can you get the truck in gear.... or does it rumble in the stick then jump slightly as it goes into gear? if this is not the case I don't think its clutch related. it may be a twisted mainshaft in the trans. does the clutch have 1 1/2 -2 in. of freeplay at the top of the pedal? does the bottom 1 in. work the clutch brake properly ? I assume that when you had the truck pulled backwards the eng was off. does the trans feel like its right shifting it with the eng. off?

I went and checked it out further. Total clutch travel is 11", pedal has resistance at ~1" depressed. Started the truck in neutral, depressed clutch and tried to shift to first, met resistance and slowly let out clutch until the shift occurred smoothly around 5" out from floor, rpm's started dropping at ~8" from floor as clutch started engaging. The truck was on fairly level ground and I tried the shift from neutral to first several times experimenting with brakes and trying to keep weight off the trans etc... It would either shift as I wrote above or would shift smoothly with the clutch at the floor. Yes, when I had the guy pull me backwards the engine was off and the front of the truck was on the downhill. The previous jam, that I was able to get out of, was about the same incline but the front of the truck was on the uphill.

[76cmc]

I hope this picture was added. I guess to add pictures to a thread, you have to upload to "gallery" and then link to the post via "My media". This is a pic as I just drove on to the Tacoma Narrows bridge. Will add other pic's of the truck later today. Thanks

Pic's of the truck. The inside of the box is full wood floor and walls, too full of my shop stuff to take a picture of.

[76cmc]

It could be clutch related. My Pete when the new clutch was installed wouln't get out of gear sometimes for nothing. had to let the clutch out a bit and get the truck to move and then get it out of gear

Odd deal on my truck is that if I try to shift from neutral to first from a dead stop when the load is against the gears, something jams. The truck won't move at that point, just slip/burn the clutch. As I mentioned, you don't even feel the shifter move as you attempt the shift but it goes into the jam mode. Then you're screwed, can't pull back into first or move to neutral. Now that I'm aware of the issue, I shift to neutral before coming to a stop. If I forget, then I let the clutch out a little to get the truck in motion before I shift out of first.

[76cmc]

Welcome to the doghouse!!! Sounds like you had a great trip.

When you go down to the reply box in the lower right corner is "more reply options" this will ask you to "browse" to your picture library, open your picture and attach and post.

Tried that and much easier to add pic's. Thanks

[76cmc]

Welcome!

The engine model number is stamped on the cast timing chain cover just in front of the injection pump. ENDT675 is a 237 hp. for example.

Can't help with a cruise control system. Clutch may need adjustment and the fork in the trans may be worn out.

Oh yeah, we need some pictures

An AC compressor is sitting right above that area so couldn't see the number. Any other places the ID might be? Added some pic's below. thx

[gearhead204]

let me first back up and welcome you to the evergreen state! I'm on the other side of the "hill" so to speak. Your dilemma about the smoking clutch has me thinking the trans is going into 2 gears at once, other wise it should move the truck one direction or another. if you get stumped call c.w.grove in kent . they are a independent mack shop. that should be better help than transport equipment center.

[maint1]

Welcome, I am agreeing with Rob, sounds like it is in two gears, like your truck, another good adventure.

[nasty51ford]

Love the truck, and my thoughts when I was reading about your problem was that it is stuck in two gears also! Good luck, I'm new on here too, and there are a great bunch of people on here!

[mrsmackpaul]

It's not coming out of what ever the gear was when you rolled to a stop and when you put it in first gear you are then getting stuck in two gears it will be a cheap fix will have to pull the floor out and see whats not lined up or what has worn off then just weld the piece up that has worn down or adjust dog on the rod in the top of the box to close the gap up ( you will see what Im on about when you have the top off the box ) I reckon it will take longer to get all the stuff out of the cab than it will to fix the problem wont be the clutch as it only happens in one gear oh yeah welcome and what a great looking truck looks real handy for bringing all sorts of bargins home gotta love the tail gate lifter

This fix I reckon you should be able to do your self no problem at all

Paul

[HarryS]

Welcome. Very nice truck and box. Sounds like a fun trip. Hope you can get the trans straightened out with not too much trouble. PS Looks like something cool under cover parked next to your truck

[thomastractorsvc]

Welcome, nice looking Mack like the set up. Its always great to hear about a trip with old iron.

[Freightrain]

Neat truck! Love the stainless box.

Takes some finesse to get the hand throttle adjusted just right. Have to slide the little pin up a bit farther. When I fixed mine I had the same problem. Just moved it a bit more and now I can get wide open throttle!

Here is mine, you can see the brass pin on the cable sticking through the hole on the throttle linkage:

Mine has no turbo, so you can see it from the top.

Most guys use Photobucket to post pictures here. You can save them to your gallery also.

[mrsmackpaul]

Welcome. Very nice truck and box. Sounds like a fun trip. Hope you can get the trans straightened out with not too much trouble. PS Looks like something cool under cover parked next to your truck

might be more more than just one thing hiding in the background you blokes have sharper eyes than me that is one cool looking truck

Paul

[mowerman]

nice welcome and good luck...bob

[Bobby j]

Good looking "b" also love the old style rounded box........welcome....lots of good people on here.......bobby j.

[gearhead204]

putting 2+2 your trip over the narrows and the fact that your house and surrounding trees don't have moss on them I'm guessing your around Purdy-Silverdale area, if so watch out for the wimmins correctional facility! don't be trying to get behind bars