bad vibration
Thread Starter
|
Posting Guru
Joined: Aug 2006
Posts: 1,049
Likes: 0
From: Perry Georgia
bad vibration
We just got my sons 1976 Ford Explorer back on the road. It is a 1976 F100 Explorer extended cab that we replaced a 360 with a 300 six backed up by an FX automatic transmission. Between 45 and 50 mph the whole truch has a really bad vibration but above and below those mph it drives smooth. Besides the engine and transmission swap we had the front driveshaft tube replaced by a guy that has done driveshaft extending and shortening for rockcrawlers. I also Replaced the rearend seal. The "U" joints all felt good. Any ideas?
Cargo Master
Joined: Apr 2009
Posts: 3,038
Likes: 4
From: South west Idaho
You may not have the right converter flexplate to get the balance correct. Did you use one that was made for the 300 engine ? Wrong one will beat the bearings out in short time if it's vibrating a lot.
Lead Driver
Joined: Nov 2006
Posts: 5,217
Likes: 506
From: Pa.
It could be anything from a missing wheel weight to a nut missing from a u-joint u-bolt .. There are so many possibilities there .. How was it before drive shaft work ? Is it at the tires or in the drive train ? Also agree with Jim's idea
Cargo Master
Joined: Apr 2009
Posts: 3,038
Likes: 4
From: South west Idaho
Okay I believe it is something else then. Any time i had one with the wrong flywheel or flexplate they would shake all of the time. I believe there is the possibility of the drive shaft you had work done to is out of balance or has a bad U-joint in it. Maybe even they joint where the couple together .
Posting Guru
Joined: Dec 2009
Posts: 2,134
Likes: 1
From: Mississippi
Maybe the driveline is out of phase? DRIVE LINE PHASING
make sure the u joints are on the same plane.
make sure the u joints are on the same plane.
Thread Starter
|
Posting Guru
Joined: Aug 2006
Posts: 1,049
Likes: 0
From: Perry Georgia
The guy that did the driveshaft made sure everything lined up. He had me bring all of the driveshaft so there wouldn't be any problem with the driveshaft.
Trending Topics
Lead Driver
Joined: Nov 2006
Posts: 5,217
Likes: 506
From: Pa.
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
Cargo Master
Joined: Apr 2009
Posts: 3,038
Likes: 4
From: South west Idaho
In your first post you say it is a F-100 , so is it a short box ,wheelbase , or long box ? I have a 73 F-100 with the short box and it has a one piece drive shaft , I had a 79 F-100 and it was the same . They had a 302s , one with a 4 sp. and the other with 3 sp , that i changed to a C/4 later , both 2 wd. All three super cabs with two wd I had came with the two piece shaft.
Senior User
Joined: Mar 2004
Posts: 280
Likes: 2
From: Alabama
Lets assume there was no vibration before the engine swap. Can you feel a vibration in the truck with your foot on the brake, truck in gear while raising the RPM? I don't know if you have a tach hooked up but 45 -50 mph would be about 2100-2300 RPM?
If you can feel it vibrate in this situation than you can probably rule out the drive train and start looking at the engine. I had a very similiar situation at about 2200 rpm going down the road, felt like a wheel was going to fall off. It turned out my 302 didn't like the richporter distributor I put in. I can't explain it, don't know if the gear was wrong for the after market cam that the PO put in but it's gone now.
If you can feel it vibrate in this situation than you can probably rule out the drive train and start looking at the engine. I had a very similiar situation at about 2200 rpm going down the road, felt like a wheel was going to fall off. It turned out my 302 didn't like the richporter distributor I put in. I can't explain it, don't know if the gear was wrong for the after market cam that the PO put in but it's gone now.
Thread Starter
|
Posting Guru
Joined: Aug 2006
Posts: 1,049
Likes: 0
From: Perry Georgia
I think we have it figured out. Comparing the middle carrier bearing of the 1976 F100 to my F250 middle carrier bearing the 1976 seems to have more side to side play. We're going to replace the carrier bearing this week and I do have one question. How does the old carrier bearing come off and how does the new go on?