I don’t know what you meant by the SROD OD. What is add on OD? OD is obviously overdrive.

Does this mean you can run 45 mph in 5th gear with the M50D? But is better at 70?

Thanks for your patience.

Phil

 

SROD = Single ROD it was a transmission Ford used that was over drive.

Yes OD = over drive

I have Advance Adapter Range Spliter over drive that I added to my truck.
It fits between the motor & my NP435 (granny 4sp) turning my 4sp into a 8sp transmission.
Now some of the ratios are too close together to split all gears when not pulling a heavy load so I split mostly 3rd and 4th
Being a granny first you start in 2nd> 3rd> 3rd over>4th> 4th over making it a 5sp over drive.

With my 300 six I can run at 45 MPH in 4th over, it that 5th or 8th
I guess my 4th over (5th) would be the same as 5th in the M5OD as it is a over drive also.
The 300 dose have good low end power but is a little doggy at 45 MPH in over drive.

The sweet spot for the 300 is about 1800 RPM
With out over drive and 55 MPH, the speed limit back in the 80's, was 1800 RPM
The speed limit here is 70 MPH and with over drive I am at the sweet spot of 1800 RPM.

I think what I was saying is with your 2.47 rear gear and the over drive you may find your truck a little doggy below 50 MPH in over drive is all.
You will know once you have it on the road.
Dave ---

 

i googled the adapter you referenced. I don’t thing it will fit on a M50D Mazda trans…. I am looking forward to getting the trans in…

Once the trans is in, I would like to change out the rear end and maybe install disks. You mentioned 2.75. What do you recommend? I use the truck on a weekly and sometimes daily basis around town. I don’t use it for expressway much now as the 3 speed gets horrible fuel economy. I won’t pull much. Maybe a small 12’ single axle trailer for wood or moving small loads. Thanks for your feedback Dave.

For future reference I purchased the pedal assembly from a truck junk yard in Silvis IL. They will ship it. 2 & 92 truck parts have a stack of those pedals if someone just wants the pedal assembly like what I did versus a parts truck.

Phil

 

The Advance Adapter OD I have is not made anymore.
Think I got one of the last as it was just as Covid hit and had to wait for it to be made.
I am guessing between not selling many now that there are some other options and letting staff go because of Covid they just though best to drop the unit?

You also would not want to add a second OD unit to a OD transmission for double OD unless you were running a really really low rear gear something like 5.13 and 29" tall tires and then first and maybe second gears would be so low you would never use them?
Also with any rear gear ratio, tire size and transmission you dont want to drop the cruise RPM to low and bog the motor down as that is not good either.

I would say get the M5OD installed and use the truck for a few months to "feel it out" as you may find it is ok with the rear gear you have for what you use the truck mostly for. Then if you find you need or want to make a change report back in a mew post.
We will need to know what rear gear ratio you have 2.47?, transmission & ratios you have if you can find them, the size tires and what you use the truck for mostly.
You did say you pull a trailer and load how heavy, how often, how far and the type of roads. Oh and the speed / RPM in what gear, OD?
If you live out in the flat land you can gear 1 way but in the hills or mountains would be 2 different gearing for each.

I knew my car trailer would be between 5K and maybe 6K but not pulling it vary far, maybe 100 miles round trip? And not often as I have a truck just for pulling this trailer. It would be on hilly roads but nothing too steep.
I also knew with the rear gear of 2.75 I would need a transmission with a low first gear and why I kept the granny first gear.
Most of the driving I have done over the 5 years it's been on the road (28+K) have been empty and high way of 70+ MPH.
So with the gearing, transmission and OD it works good for me.
If I was to pull the trailer more often and longer distance I would change the rear gear to maybe 3.55 or 3.73 but it would have to be a LOT MORE pulling to do that.
For you and what I know so far and wanted to change the gear I would look at what ratio the truck had that you got the M5OD from and maybe go with that?
I think it has been posted 3.08 was standard with 3.55 as a option but not 100% sure on that with the M5OD trucks?

There are also web sites that you can put the transmission ratios, rear gear and tire size into and it will give you the RPM for each gear you are in.
Lot of fun to play with. I like this one to play with for information https://www.garysgaragemahal.com/calculators.html

Sorry so long retired and nothing to do
Dave ----

 

I just went over this again, what year truck did your pedals come out of and what will they be going into?
I ask as the 87> pedals are not a bolt in, the brackets are different.
I also dont know if you can swap the clutch cross shafts between them?
For sure the 84 to 86 pedals swap into the 80 - 86 trucks.

Also when MPG are you getting now and at what speed?
Dave ----

 

The pedal assembly came out of an 85.

fuel economy right now is roughly 11 to 12 miles a gallon. I don’t take it out on the expressway like ever. I usually have it in the ballpark of 50 miles an hour when I am traveling the back roads. The three speed is killing me.

Now for a additional clarification.

I received the metal plate that I ordered from bronco graveyard. Currently the truck has manual brakes. I believe that the plate is set up for trucks with power brakes. I do eventually want to put power brakes in the truck, but I was wanting to hold off until I can get the transmission and a few other items done first.

Do I have a choice? Do I have to put the booster on so that I can install the plate?

I believe the bottom two holes in the plate go on the bottom, two holes of the booster, but I wanted to have clarification on that.


Mounting holes/ bolts of brake master cylinder..

Bracket approx location?


Thank you. @FuzzFace2
Phil

 

I cant say much on the plate as my 81 uses linkage not a master / slave.

I can tell you all the holes to mount the booster are there for when you do the power swap.
So if the plate uses some of the brake master holes then you are good and should be able to keep the manual till you swap in the booster.

Now for what you do the booster swap you will need a power brake pedal as the pin for the rod is in different places between the manual & power pedals.
Do your home work but I found the rear wheel cly were the same between the 2 systems just the shoes & drums where different sizes.
The calipers I also found had the same size pistons but are different size so the mounting is different as are the pad size to fit the calipers.
So the master, wheel cly. and calipers all have the same fluid sizes between manual & power and why I kept the manual brakes on all 4 corners.

In short I mounted the power booster with the power brake pedal (whole pedal assy. from my parts truck) as it bolts right in.
Left the manual parts at the wheels and they work pretty good for the last 5 years and 28K miles.
Dave ----

 

Roger. Meant to include @Franklin2 on plate orientation. He provided the link.

I believe the 85 pedal assembly I have is power brakes. Isn’t the pin location that is circled what you are referring to?See pic.


This is what I am planning for the moment. When I go to swap out the pumpkin I will have everything apart and I “may” consider installing disks…..but I don’t really need it. The rear already have the 11” drums.

Thanks.

Phil

 

Like Fuzz said, the holes are already there for the plate no matter if it has a booster or not. As far as your new brake pedal assembly, if it's for power brakes, I would go ahead and install the booster. If I remember correctly, the pin on the brake arm is in a different spot depending on if it's power or manual. You can rig things to make it work, when I got my first truck I was dirt poor and could not afford a new booster. So I rigged it to have manual brakes till I saved enough money to get a booster. If you are just waiting and really have the money, go ahead and buy the booster everything will fit up and work much better.

P.S. Do the manual master cylinders have a different mounting bolt spacing than the ones that mount to the booster? I can't remember.

 

To see if it is for power measure from the pivot to the pin on both brake pedals, they should be different.
I have pictures of the 2 but I dint remember what one is what so it really dose not help.
It is also 2 damn hot to go digging thru my parts bins to find the manual pedal assy. and the hydro. pedal assy. that I think was power brakes.
So if yours measure different then I would say you got a power pedal.

Any way to get the booster & master from the pedal truck for cores when the time comes?
If you go disc out back you will need to find a disc / disc master as the rear calipers will use more fluid.
Even pulling a trailer that I sometimes do I dont see the need for rear disc.
Dave ----

 

I believe the pin on the power setup is lower. That is less mechanical advantage when you press on the pedal, and I also believe that is why the brake booster mounts every thing at a slight upward angle. The manual master bolts flat to the firewall, so it lines up with the pedal with the higher pin. And the higher pin gives you more leverage when your foot presses the pedal, probably needed on a manual setup. So higher pin for manual, lower pin for power.

 

DaveF I dont know on the master spacing as I was not really looking at that.
I dont know how well I could measure it as I still have the manual master some where and the power on my truck but the heat here keeps me in the AC
I did have to pull and check a tire on the pick up so I may get out there early.
Dave ----

 

Bracket goes on the inside, rotate 90 degreed. The big ring goes around the steering wheel.

 

You know I was thinking it had to be turned but not ever installing one I could not picture how it all fit in there.
I think someone cut the part that fits around the column so they did not have to undo it to fit the plate.

That is the large plate right and the smaller one did not fit around the column IIRC.
Dave ----

 

I do not know if it was these trucks or something else, but the difference was small and a little file work cured it. That is how close it was.