Pinion play
Thread Starter
|
New User
Joined: Feb 2013
Posts: 11
Likes: 0
From: Hamilton
Pinion play
Hey All,
I had a question about how much is too much in regards to pinion play? I just replaced the U-joint on the rear end that lasted about 2 years and 10,000 mi. This is the second replacement in 5 years of ownership. The truck is relatively stock 79 F150 no lift on 31" tires with a 9" rear. I'll try to post a video with the thread but I have roughly 1/4"-1/2" of play. I am thinking this is what is eating the U-joints. Thoughts?
I had a question about how much is too much in regards to pinion play? I just replaced the U-joint on the rear end that lasted about 2 years and 10,000 mi. This is the second replacement in 5 years of ownership. The truck is relatively stock 79 F150 no lift on 31" tires with a 9" rear. I'll try to post a video with the thread but I have roughly 1/4"-1/2" of play. I am thinking this is what is eating the U-joints. Thoughts?
Fleet Owner
Joined: Dec 2009
Posts: 20,678
Likes: 83
From: NorCal
I think your rear gears are worn and it's causing the u'joint to go bad because the applied torque is torqing on the caps. Alternatively the straps are too tight and deforming the caps. The ring and pinion shouldn't be that loose.
'Time to pull the pumpkin to have a peek.
'Time to pull the pumpkin to have a peek.
Cargo Master
Joined: Oct 2010
Posts: 2,674
Likes: 16
From: Ideeho
By "play" I assume you mean when rotating the yoke? If so.........yeah pull the pumpkin and have a look. I have seen 9" rears run for a long time with more than that with no issues but that doesn't mean that its right. If its up and down "play" at the yoke, You've got bad pinion bearings but if it's that loose, you would also have a leak at the pinion seal. Beyond that, regular greasing is the key to long u joint life.
Fleet Mechanic
Joined: Feb 2004
Posts: 1,510
Likes: 333
From: Arlington,Wa
I had lots of pinion play in my F-150 for a long time. It wasn't up n down play but L-R. (I had a Lock Rite) For awhile I was going thru U -joints until I got the drive shaft balanced. After that I had no U-joint issues for a long time. Also make sure the 2 ends of the drive shaft (meaning the U-joints) are "in phase" and not 180 out from each other.
Fleet Owner
Joined: Dec 2009
Posts: 20,678
Likes: 83
From: NorCal
Yes, it's rotational play shown in the video.
Thread Starter
|
New User
Joined: Feb 2013
Posts: 11
Likes: 0
From: Hamilton
I think your rear gears are worn and it's causing the u'joint to go bad because the applied torque is torqing on the caps. Alternatively the straps are too tight and deforming the caps. The ring and pinion shouldn't be that loose.
'Time to pull the pumpkin to have a peek.
'Time to pull the pumpkin to have a peek.
Thread Starter
|
New User
Joined: Feb 2013
Posts: 11
Likes: 0
From: Hamilton
I had lots of pinion play in my F-150 for a long time. It wasn't up n down play but L-R. (I had a Lock Rite) For awhile I was going thru U -joints until I got the drive shaft balanced. After that I had no U-joint issues for a long time. Also make sure the 2 ends of the drive shaft (meaning the U-joints) are "in phase" and not 180 out from each other.
Trending Topics
Cargo Master
Joined: Oct 2010
Posts: 2,674
Likes: 16
From: Ideeho
Sorry didn't catch the fact that he had posted video.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Cargo Master
Joined: Jun 2010
Posts: 2,113
Likes: 4
From: Iowa
I didn't watch the video as data is limited but rotational slop in the rear differential will not affect the U joints and as rusty as the one you have in your picture is it's likely lack of lubrication was the culprit. How often did you grease the u joint? And did you grease it on installation if it has a grease zerk as it's common for them to come with assembly grease and neads real grease added after installation.
Edit, even if you did grease the U joint religiously it isn't all that uncommon for one of the yolks to not take grease and rust..... I'm a farmer and have hundreds of the darn things and have seen it all.
Edit, even if you did grease the U joint religiously it isn't all that uncommon for one of the yolks to not take grease and rust..... I'm a farmer and have hundreds of the darn things and have seen it all.
Thread Starter
|
New User
Joined: Feb 2013
Posts: 11
Likes: 0
From: Hamilton
The U-Joint was greased at install, It was in for about 2 years I think I greased it once or twice. I also used to live in the only temperate rain forest in North America 150+ inches of rain a year. It seems like with the rotational play it would slam the U-joint every time power is applied or removed.
Cargo Master
Joined: Jun 2010
Posts: 2,113
Likes: 4
From: Iowa
I am not trying to start an argument and I'm not saying that something isn't wrong with your trucks rear end but I have replaced countless U joints that looked exactly like that and every one of them has been caused buy lack of lubrication and have never seen a u joint fail that way from impact damage.
Some have been directly caused by my lack of maintenance but the vast majority have been just because the grease only pushes into three of the four yolk bearings and the fourth one without lubrication and rusts and fails.... It is way more common than you would think
Some have been directly caused by my lack of maintenance but the vast majority have been just because the grease only pushes into three of the four yolk bearings and the fourth one without lubrication and rusts and fails.... It is way more common than you would think
Cargo Master
Joined: Jun 2010
Posts: 2,113
Likes: 4
From: Iowa
Tuned
Joined: Jun 2014
Posts: 475
Likes: 34
From: Vermont
Absolutely agree with what Twigs said!! Not saying that is what caused this particular failure but it sure fits the bill. I worked in farm dealership repair shops in an earlier pre-body shop life and saw a zillion driveline u-joint failures (and I truly mean a lot on a daily basis!!). Many ,many reasons but very common for 1 cup NOT taking grease. Still notice to this day after replacing a u-joint that the grease, at times, will squirt out on maybe 3 cups and not the 4th and it always makes you wonder and sometimes swear. Also the chance of 1 roller being out of place when the cups were installed/pressed in originally. There is a technique I use to install the cups where there is NO chance of a roller or 2 tipping over. Gary
Elder User
Joined: Sep 2014
Posts: 862
Likes: 7
From: like subarctic, brrr man!
I go for those non-greaseable sealed for life u-joints. The part person told me they use better seals or that over-greasing them wrecks the seals. Whatever it is, they last longer for me, even if I'm doing the Moses through puddles and melting ice roads.
Thread
Thread Starter
Forum
Replies
Last Post
collinrandle
1973 - 1979 F-100 & Larger F-Series Trucks
13
Oct 20, 2015 05:40 PM
88FordF-150
Clutch, Transmission, Differential, Axle & Transfer Case
3
Nov 8, 2005 07:10 AM
79BroncoJD
Clutch, Transmission, Differential, Axle & Transfer Case
7
Nov 10, 2002 12:02 AM
Polkat
Clutch, Transmission, Differential, Axle & Transfer Case
2
Sep 27, 2002 06:16 PM