1990 F150 M5R2 reverse gear endplay
Thread Starter
|
4wd High
Joined: Apr 2026
Posts: 9
Likes: 1
1990 F150 M5R2 reverse gear endplay
Just about finished with my first transmission rebuild on my M50DR2 and everything is tight and I was able to adjust preload on main shaft, but the only thing I’m concerned about is the reverse gear. Brand new reverse gear and slider, but it’s got a tiny bit of slop and when I turn the output shaft by hand it wants to pop up a tiny bit. I’m concerned about it popping out of gear in reverse, does anyone know if there’s a shim I can get to adjust that endplay? I suppose I could try and make one with some steel that’s the right thickness and a couple hole saws….
Hotshot
Joined: Jul 2020
Posts: 10,349
Likes: 2,588
From: Near Salt Lake City
There should be some clearance there (very little) .010" or less
That reverse gear has a caged roller bearing for it to ride on
** Maybe those are missing?
How much up and down?
If it is moving up and down vertically, maybe the roller bearings, the gear or the shaft is worn
The end play adjustments for your M5ODR2 are for the mainshaft and cluster shaft, adjusted by select fit shim washers
Google M5ODR2 end play checks and specifications and it will show you a procedure and the specs
There is a 2 piece thrust washer for the reverse gear shaft, it;s also selective fit
That reverse gear has a caged roller bearing for it to ride on
** Maybe those are missing?
How much up and down?
If it is moving up and down vertically, maybe the roller bearings, the gear or the shaft is worn
The end play adjustments for your M5ODR2 are for the mainshaft and cluster shaft, adjusted by select fit shim washers
Google M5ODR2 end play checks and specifications and it will show you a procedure and the specs
There is a 2 piece thrust washer for the reverse gear shaft, it;s also selective fit
Thread Starter
|
4wd High
Joined: Apr 2026
Posts: 9
Likes: 1
Hi, the cluster shaft, slider, and gear are brand new from the same supplier, roller bearings are in and look good, split thrust washer is tight and 5th gear/synchro assembly feels tight and good, and I’ve got about .022” end play in the gap circled.
I made a custom washer yesterday out of grade 80 steel metal roofing material, but I realized I made it for the wrong shaft contour and there’s really nowhere to put a thrust washer to adjust the end play. The only thing I can think of is maybe the shaft or gear is slightly out of spec
I made a custom washer yesterday out of grade 80 steel metal roofing material, but I realized I made it for the wrong shaft contour and there’s really nowhere to put a thrust washer to adjust the end play. The only thing I can think of is maybe the shaft or gear is slightly out of spec
Hotshot
Joined: Jul 2020
Posts: 10,349
Likes: 2,588
From: Near Salt Lake City
How far is the gear moving up and down?
You cannot just find the right Mazda shim?
If you are sure the bearings are in there, it will most likely be okay depending on how much movement there is
You need .009- .013" clearance on that 5th-reverse shaft
The shaft clearances are critical on that 5 speed for shift quality (any trans really)
You cannot just find the right Mazda shim?
If you are sure the bearings are in there, it will most likely be okay depending on how much movement there is
You need .009- .013" clearance on that 5th-reverse shaft
The shaft clearances are critical on that 5 speed for shift quality (any trans really)
Thread Starter
|
4wd High
Joined: Apr 2026
Posts: 9
Likes: 1
There is no clearance between the split shim and the face of the synchro assembly, but there’s .022” above the split washers in the reverse gear which is visible in that gap. So that means there’s not enough clearance on 5th? I figured it needs to be tight but smooth.
Trending Topics
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
DFAR
2017 - 2022 Super Duty
18
Feb 13, 2022 08:35 AM
Leland
Clutch, Transmission, Differential, Axle & Transfer Case
1
Apr 8, 2002 02:42 AM