Aloha, ‘67 M725 no reverse

[Shark]

Hello all,

Picked up a weathered ‘67 M725 Ambulance up about 5 months ago. Has a 327 sbc conversion adapted to stock transmission. All forward gears fine but just won’t engage in reverse, like I can’t get it all the way in position. Any clues?

 

[swbradley1]

What transmission?

You mentioned an engine conversion.

 

[Recovry4x4]

I would suggest that someone had the cover off and when they put it back on, the shift fork missed the collar. With that said, my experience comes from an SM465, not a T18. By the way, take a pic of the trans. If you haven't looked yet, it might have an SM420 or SM465. Both easily hook up to the SBC and from the cab would appear similar to stock.

 

[NDT]

Stock is T98. I would pull the transmission cover and look for worn or broken shift forks.

 

[swbradley1]

T98 is also used in Ditch Witch trenchers just in case you go looking for one.

 

[Shark]

Thanks for all the replies.

Have no photos of engine or transmission. It has been sitting in back of a 40’ conex container, nose in, since the day I had it delivered to keep it out the salt air. I’d have to drag it outside container just to get to front of truck (only way in and out is through back door because of width, and it almost touches ceiling of conex).

It has the T98, that I’m sure. Found one a while back on the mainland, but held off buying until I was sure it possibly wasn’t just a small known issue.

Right now I’m wrapping up a restoration on an old El Camino and will be getting to this truck within a month.

Can anyone recommend a supplier for parts, such as master cylinder, brake shoes and drums?

 

[m38inmaine]

There is also a safety device so you have to depress a spring loaded plunger to engage reverse, it may be stuck/rusted.

 

[Shark]

Ahh, do you have a photo or location where it is located? Thanks

 

[NDT]

Guys the M715 series don't have a reverse lockout button.

 

[67Beast]

Thanks for all the replies.

Can anyone recommend a supplier for parts, such as master cylinder, brake shoes and drums?

The 2 major players in parts for these trucks is Memphis Equipment and Vintage Powerwagons, but there are a ton of small vendors that have various items and ebay is often helpful on finding some of the odd parts. Being a M-series vehicle, means that there are several common parts that are the same as many other military vehicles. Good luck and have fun working on it, and post plenty of pics when you do. I have a 67' M725 that I've restored along with it's brother vehicle a 67' M715.

 

[m38inmaine]

Here is a picture of the shifter assembly I rebuilt, you can see the end of the plunger in the center to the left, the part the shifter hits against is hidden in the center. So what does this spring loaded plunger do ?, it prevents the shifter from moving the shift rail unless you lever that plunger out of the way, perhaps it's not reverse. My spring loaded plunger was stuck from a burr where the plunger sticks out, it's working correctly now.

 

[NDT]

Here is a picture of the shifter assembly I rebuilt, you can see the end of the plunger in the center to the left, the part the shifter hits against is hidden in the center. So what does this spring loaded plunger do ?, it prevents the shifter from moving the shift rail unless you lever that plunger out of the way, perhaps it's not reverse. My spring loaded plunger was stuck from a burr where the plunger sticks out, it's working correctly now.

Sorry I mis-interpreted your earlier post.

 

[m38inmaine]

No problem NDT, this is how we learn, so is that plunger a reverse lock out ?

 

[Shark]

Aloha again, didn’t want to start a new thread..... finally getting ready to move my ambulance to the house this weekend so I can put some work into it.

Unfortunately, the tires on it are so old that moving it even a few feet results in large strips of tread to fall off. Because of this, I need to flatbed it to my house. Can I put regular 16” truck tires on stock wheels with inner tubes for the time being? Not in a position at the moment to afford correct tires, mostly because of outrageous shipping costs here to Maui.

 

[NDT]

Sure I would. Technically you are not supposed to put tubes in tubeless tires but for what you are trying to do should be fine. Yes the 9.00-16s are very pricy now and surplus ones are ancient.

 

[67Beast]

Yep putting some regular 16" tires on for the time being to move around should be fine. If you plan on making it long term, you need to use radial tubes instead of the stock bias tubes otherwise the tubes can fail. I've had 36x16 Swamper radials with radial tubes on my M715 since 2004 without any problems.

 

[Shark]

Good to hear, have Swampers too.

Just curious, are there wheel adaptors somewhere out there available for fitting common 6 and 8 lug wheels?

 

[Shark]

Pulled out the Ambulance from being stored in 40’ container for a year and just have to swap out the brake master cylinder so can stop. How about that tire? From 1987, all of them, LoL

 

[Shark]