M5odr2

[Socnarftrucks]

I can say from experience that installing the big one is a pain. If I wasn't in a hurry I'd consider selling the big one and ordering the smaller one. As Jim said, when going from mechanical to hydraulic your firewall isn't hurt and the small one will be adequate. But the big one will certainly do the job if you don't mind installing it.

Thanks Gary!! Too late, I’ve already

Drilled the holes and it was a real pain. Wish I had known about the E3TZ-7K509-A support…

[Rembrant]

You want an '83-'87 master with the two bolts one above the other.

Later masters have the bolts on the diagonal and the embossed firewall isn't laid out for these.

I went through this a few years ago. Nice thing is that other than the diagonal bolt pattern, they're identical. The embossed firewall only showed up in 1983, so an earlier truck it will just be smooth.

I installed one in a 1980 cab. Drilled the holes and it worked just fine. I basically made a homemade small bracket:

 

[ArdWrknTrk]

You want an '83-'87 master with the two bolts one above the other.

Later masters have the bolts on the diagonal and the embossed firewall isn't laid out for these.

I went through this a few years ago. Nice thing is that other than the diagonal bolt pattern, they're identical. The embossed firewall only showed up in 1983, so an earlier truck it will just be smooth.

I installed one in a 1980 cab. Drilled the holes and it worked just fine. I basically made a homemade small bracket:

Right. You made one, but there's a reason the E3TZ and E7TZ firewall braces are different.

And that is because the master cylinder studs moved so the brace is punched differently.

 

[Rembrant]

Right. You made one, but there's a reason the E3TZ and E7TZ firewall braces are different.

And that is because the master cylinder studs moved so the brace is punched differently.

 

Oh interesting, I didn’t know they were different. The aftermarket ones all fit both don’t they? I installed the big one from Terrapin in my ‘84, and removed the small one that was in it. By the time I did the 1980 I just made the small one.

[ArdWrknTrk]

Right. You made one, but there's a reason the E3TZ and E7TZ firewall braces are different.

And that is because the master cylinder studs moved so the brace is punched differently.

 

Oh interesting, I didn’t know they were different. The aftermarket ones all fit both don’t they? I installed the big one from Terrapin in my ‘84, and removed the small one that was in it. By the time I did the 1980 I just made the small one.

I honestly don't know about the ones Terrapin made.

I made the mistake of ordering the E7 version of the small reinforcement from the dealer thinking "I've got an '87!"

But no....

I suppose just like the 460 EFI heads that were E7TE and went onto '88 model year trucks, starting in September after the lines were retooled.

[86 12 Brutus]

2000 rpm at 60 is about what I would expect in fourth gear. I bet the truck runs and drives great and goes through the gears good also. I am using a different goal on builds as I'm wanting to keep mpg at least a consideration. I like 2000 rpm to be giving 70 mph at least 75 would be about right imo.

I don't remember the od ratio of the m5 but I have the aod/w (modified with .70 od) in dolly with the roller 5.0 and 3.73 rear gear and I cruise at 2000 rpm at 72 mph on stock size tires

I may have the driveshaft, i think if i remember correctly my parts truck has that transmission and is a single cab short bed 88

[Socnarftrucks]

Regarding the hydraulic parts...you have to be a bit careful what you use, as the parts changed a few times over the generations. The 1984-1986 master cylinders are the same as the 1987-1991 master cylinders, except for the bolt pattern:

If you have to drill holes in the firewall anyway, it doesn't really matter which master cylinder you use, but I tried to stick with a Bullnose master, and the for the hydraulic line and concentric slave cylinder, I ordered all new parts for a 1991, for both trucks. The master cylinders changed again in 1992, and you can use one of them also, but if you do then you'll need a 1992-up hydraulic line and slave cylinder.

If you're pulling the hydraulic parts from a donor truck, pull the whole works. If you're buying new parts, then go with a 1984-1986 clutch master, and then order a line and slave cylinder for 1988-1991.

Just verifying: M5ODR2 transmission came out of a 93. I have installed the concentric save cylinder, master cylinder, and line for a 93. Bleeding (even bench bleeding)and adjusting the clutch has proven very challenging and frustrating

….

 

[Gary Lewis]

Just verifying: M5ODR2 transmission came out of a 93. I have installed the concentric save cylinder, master cylinder, and line for a 93. Bleeding (even bench bleeding)and adjusting the clutch has proven very challenging and frustrating

….

Yes, bleeding these hydraulic systems is frustrating. You can't seem to get all of the bubbles out, probably because the lines are so small.

Some said to hang it on a ladder to let the bubbles get out. But I already had it installed. So I bled it until I could get enough clutch action to drive it. Had the clutch to the floor to start it and the truck moved but the engine started. Drove around the neighborhood pumping the clutch and pretty sure the bouncing allowed more movement. Finally all of the bubbles were out.

[Socnarftrucks]

Yes, bleeding these hydraulic systems is frustrating. You can't seem to get all of the bubbles out, probably because the lines are so small.

Some said to hang it on a ladder to let the bubbles get out. But I already had it installed. So I bled it until I could get enough clutch action to drive it. Had the clutch to the floor to start it and the truck moved but the engine started. Drove around the neighborhood pumping the clutch and pretty sure the bouncing allowed more movement. Finally all of the bubbles were out.

Thanks Gary! I will remove the MC again and

Bench bleed it hangin on a post or a ladder and gently tapping on the line too. First and reverse didn’t engage

last time so I might have to push it out and try your bouncing method.

[Gary Lewis]

Thanks Gary! I will remove the MC again and

Bench bleed it hangin on a post or a ladder and gently tapping on the line too. First and reverse didn’t engage

last time so I might have to push it out and try your bouncing method.

The problem I had was that I couldn't disengage via the clutch. So I started it in gear, albeit with the clutch on the floor to run the starter. But I could drive it, slowly, in 1st gear.