Drivetrain slop

Clutch, transmission, rear axle

Moderators: FORDification, 70_F100

Post Reply
User avatar
68FORDJBM
Blue Oval Fan
Blue Oval Fan
Posts: 576
Joined: Mon Oct 12, 2009 3:12 pm
Location: Bothell, WA

Drivetrain slop

Post by 68FORDJBM »

I started hearing a clunking that I suspected was coming from the drivetrain because I could hear it at low speeds while speeding up or slowing down. Got underneath and sure enough when a my wife gave a little push while in park to get the truck rocking forward and back I could see and hear the clunk coming from where the driveshaft joins the tranny and differential. I'm assuming a bushing or joint is going out but what end? What parts should I order to get it fixed?

Its a 1968 F100 Ranger with a 360 and auto transmission. I think its a C6 tranny?

Thanks in advance.
User avatar
HIO Silver
100% FORDified!
100% FORDified!
Posts: 1970
Joined: Sat Jul 23, 2011 11:31 pm
Location: Devil's Mountain, CA

Re: Drivetrain slop

Post by HIO Silver »

Firmly grab and and wiggle the driveshaft... Slop?

Prolly the U-joints... they are always replaced as a set so all have the same amount of installed time. If one goes bad, then the others may not be too far behind.
70 F100 LB 2WD, 360FE, E-Street EFI, TKO-500, 76K original miles.. follow my rebuild: The Lo-Buck Bumpside
71 F250 LB, 2WD, 360FE, T18, PS, PB, D60 with 4.11s
73 F100 SB 4WD, 390FE, NP435, +4 on 35s

01 Ferrari 360 Spider F1
01 F150 SuperCrew Lariat 4WD
01 PT Cruiser Limited (DD)
68 Mustang
65 Mustang
User avatar
68FORDJBM
Blue Oval Fan
Blue Oval Fan
Posts: 576
Joined: Mon Oct 12, 2009 3:12 pm
Location: Bothell, WA

Re: Drivetrain slop

Post by 68FORDJBM »

Thanks, I'll start with a new set of U-joints. They haven't been changed as long as I've had the truck so they are due for replacin'
User avatar
HIO Silver
100% FORDified!
100% FORDified!
Posts: 1970
Joined: Sat Jul 23, 2011 11:31 pm
Location: Devil's Mountain, CA

Re: Drivetrain slop

Post by HIO Silver »

Don't just go willy-nilly replacing parts... Ya gotta do more investigation. I said "probably u-joints"... Heck, it could be a bad carrier bearing but that's not the norm.... Crawl under there......
70 F100 LB 2WD, 360FE, E-Street EFI, TKO-500, 76K original miles.. follow my rebuild: The Lo-Buck Bumpside
71 F250 LB, 2WD, 360FE, T18, PS, PB, D60 with 4.11s
73 F100 SB 4WD, 390FE, NP435, +4 on 35s

01 Ferrari 360 Spider F1
01 F150 SuperCrew Lariat 4WD
01 PT Cruiser Limited (DD)
68 Mustang
65 Mustang
FoolsOnlyReadDirections
New Member
New Member
Posts: 4
Joined: Sat Jan 30, 2016 5:11 pm
Location: Springfield Oregon

Re: Drivetrain slop

Post by FoolsOnlyReadDirections »

Consider that your splined connection for your two-piece driveshaft may be binding as you slow or accelerate from a stop. It's a common issue for our trucks. My '68 is bad for this. I have to remove my shaft occasionally and gob into the female splined connection, large amounts of heavy equipment grease that "resists squeeze-out," it says. Try that.
User avatar
sargentrs
100% FORDified!
100% FORDified!
Posts: 9866
Joined: Fri Jun 22, 2007 9:30 am
Location: Georgia, Jasper

Re: Drivetrain slop

Post by sargentrs »

I suddenly developed a clunk and vibration in mine a while back. Crawled under there and found that both carrier bearing bolts had loosened up and it was swinging back and forth under there. New bolts, nuts, washers and lock washer and all was good afterwards. I have no idea how that happened!
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
User avatar
Jacksdad
Blue Oval Fan
Blue Oval Fan
Posts: 579
Joined: Sat Mar 30, 2013 8:52 pm
Location: San Diego, CA

Re: Drivetrain slop

Post by Jacksdad »

U-joints fail more often than anything else under there, and should be pretty obvious if you try to turn/move the driveshaft with your hands.
I just changed all of mine out, and one was so bad that it had no needle bearings left :eek:
1971 DRW F350 cab and chassis with an Open Road motorhome conversion, Dana 70, 352 (originally 390)/C6, PS, power front discs, and 159" w/b.
User avatar
radioactivelarry
New Member
New Member
Posts: 184
Joined: Thu Jan 08, 2015 1:55 am
Location: Northern California

Re: Drivetrain slop

Post by radioactivelarry »

68FORDJBM wrote:I started hearing a clunking that I suspected was coming from the drivetrain because I could hear it at low speeds while speeding up or slowing down. Got underneath and sure enough when a my wife gave a little push while in park to get the truck rocking forward and back I could see and hear the clunk coming from where the driveshaft joins the tranny and differential. I'm assuming a bushing or joint is going out but what end? What parts should I order to get it fixed?

Its a 1968 F100 Ranger with a 360 and auto transmission. I think its a C6 tranny?

Thanks in advance.
If you replace your U-Joints take the drive shaft to a drive line service place and have it balanced. My total cost was about $125.00 including the U-Joints. All runs super smooth now. :woohoo:
Democracy is two Wolves and a Lamb voting on what to have for lunch. Liberty is a well armed Lamb.
Ben Franklin.

My Motto: I wish I had less to do, more time to do it in and got paid more for not getting it done.
:drive:
User avatar
68FORDJBM
Blue Oval Fan
Blue Oval Fan
Posts: 576
Joined: Mon Oct 12, 2009 3:12 pm
Location: Bothell, WA

Re: Drivetrain slop

Post by 68FORDJBM »

Thanks for the suggestion! I might have to do that. That would go nicely with the balanced motor:)
Post Reply