Crank walk?
01-28-2014, 10:01 AM
#1
Crank walk?
Good morning all.
I got a question, and hopefully not a problem.
To start with, it's a '93 F150 XL 4.9 300-6
I noticed that I started getting a bit of squeal in my serp. belt a few days ago. Well today's my day off and I decided to address it. I noticed that while revving the motor a bit, the main pulley moves forward about 1-2mm's.
This is causing the belt to move around a bit on the fan pulley.
Now, my question is, is this normal (please say yes), and if not, am I looking at a teardown and rebuild with all new bearings and such.
I can do this stuff relatively easily, but I don't wanna', if I don't hafta'
Please help, because this is my daily driver, and I need to know if I should switch to my back-up car.
Thanks in advance for all of your help.
I got a question, and hopefully not a problem.
To start with, it's a '93 F150 XL 4.9 300-6
I noticed that I started getting a bit of squeal in my serp. belt a few days ago. Well today's my day off and I decided to address it. I noticed that while revving the motor a bit, the main pulley moves forward about 1-2mm's.
This is causing the belt to move around a bit on the fan pulley.
Now, my question is, is this normal (please say yes), and if not, am I looking at a teardown and rebuild with all new bearings and such.
I can do this stuff relatively easily, but I don't wanna', if I don't hafta'
Please help, because this is my daily driver, and I need to know if I should switch to my back-up car.
Thanks in advance for all of your help.
01-28-2014, 09:12 PM
#2
Senior Member
Can't say I've ever heard of this or seen it. I don't think it's supposed to do that but I would guess if you drain the oil or got your pan out to check the bottom, you might get an answer. Can you pry it out with it not running? If you pull off the belt, does the pulley wiggle? Please let me know what you find out.
01-29-2014, 06:08 PM
#4
I have seen this happen on that exact same type of engine before, it drove us crazy trying to find the source of the belt squeal and after several attempts failed we finally found the problem.
The thrust bearing on the crank shaft was worn out allowing the entire crankshaft to move back and forth, the only repair is to remove the engine and replace that bearing.
Would be a good idea to just go ahead and order a short block or crate motor if you plan to keep it.
The other problem we were having was starter engagement.
.
The thrust bearing on the crank shaft was worn out allowing the entire crankshaft to move back and forth, the only repair is to remove the engine and replace that bearing.
Would be a good idea to just go ahead and order a short block or crate motor if you plan to keep it.
The other problem we were having was starter engagement.
.
Last edited by RLXXI; 01-29-2014 at 06:12 PM.
01-31-2014, 04:28 AM
#5
Well, I got the thrust bearing confirmed by a buddy of mine.
At 274,000 miles, something had to give. So I'm gonna pull the motor next weekend and freshen it up. Good news is that it's nowhere near as bad as that eclipse motor in the vid above. There's a saying in the ricer community, "DSM = Don't Spend Money". Hehe.
At 274,000 miles, something had to give. So I'm gonna pull the motor next weekend and freshen it up. Good news is that it's nowhere near as bad as that eclipse motor in the vid above. There's a saying in the ricer community, "DSM = Don't Spend Money". Hehe.
02-22-2014, 12:23 AM
#6
When the Crank walks most moving parts get stressed.
