'85 BII U Joint Replacement

[ford4wd08]

Just a small update.

I took my boys for a drive tonight in the BII.

I had been having a debate with myself whether the vibration that I had been feeling was from tires that had sat for a while with flat spots, or was it really u joints or driveshaft vibrations.

Well luckily I have some recently paved roads by house with a hill.

Drive up to 35 mph start to hear/feel vibration. Let off the gas to coast, vibration goes away, don't feel any vibrations in the steering wheel. Give it gas or put drivetrain under load vibration is back.

Sure sounds like u joints to me. Guess I'll be rebuilding this driveshaft. Wish me luck!

 

[bobbywalter]

or angle....joints can be good and sagged springs or bad setup cause the vibes.

that shaft may have been an attempted solution.


generally you put a carden at the case and aim the diff right at it with about a 1/2 to 1 degree down for rotating load and spring deflection...

yours is fairly stock....what i do is match the angles of the pinion and output shaft and run single u-joint on each end. might take shims or re-weld perches ect....



https://www.ebay.com/itm/Prop-Propeller-Drive-Shaft-Assembly-Rear-for-90-89-Ford-Bronco-II-39-11-16/253786378715?fits=Model:Bronco+II|Make:Ford

 

[ford4wd08]

or angle....joints can be good and sagged springs or bad setup cause the vibes.

that shaft may have been an attempted solution.


generally you put a carden at the case and aim the diff right at it with about a 1/2 to 1 degree down for rotating load and spring deflection...

yours is fairly stock....what i do is match the angles of the pinion and output shaft and run single u-joint on each end. might take shims or re-weld perches ect....



https://www.ebay.com/itm/Prop-Propeller-Drive-Shaft-Assembly-Rear-for-90-89-Ford-Bronco-II-39-11-16/253786378715?fits=Model:Bronco+II|Make:Ford

I don't believe the shaft was any sort of solution. I believe it came from the factory with it.

The Bronco is 100% stock and has been sense my Granddad bought it new in December of 1984.

I know he would not have changed the output off the transfer case from a flange to a yoke.

I knew him well and promise you that he would not have had another drive shaft added, he simply would have had the stock one repaired.

I don't believe the driveshaft had ever been off until I removed it for the trans seal replacement.

I ordered the U joints this morning. Wish me luck.

 

[alwaysFlOoReD]

What's the vin number? Maybe someone can find info using that.

 

[ford4wd08]

VIN is 1FMCU14S6FUA27624

I've attached the door decal as well.

 

[Shran]

I don't believe any of the short wheelbase trucks - B2's and 4x4 shortbox Rangers - came with a rear flange ever up until the late 80's at least, and then only with Bronco II's when the CV rear driveshaft was standard. They were all double cardan style yokes because they all had double cardan joints at the t-case to correct angles related to the short wheelbase. That driveshaft certainly could have come from the factory like that, there's no sure way to know that it's NOT a Ford part... it's just very unusual and I've never seen one like it in a B2, and apparently nobody else has either. But they did do a lot of weird things in 83, 84, and '85.

FWIW I had a 1985 Bronco II with the 2.8 and A4LD and it did not have that style shaft. It had a DC front joint and a single u-joint at the rear axle. Essentially the same truck you've got. I don't know what the build date was though - beings that '85 was the first year of the A4LD, there could be several variants floating around out there.

 

[bobbywalter]

I don't believe the shaft was any sort of solution. I believe it came from the factory with it.

The Bronco is 100% stock and has been sense my Granddad bought it new in December of 1984.

I know he would not have changed the output off the transfer case from a flange to a yoke.

I knew him well and promise you that he would not have had another drive shaft added, he simply would have had the stock one repaired.

I don't believe the driveshaft had ever been off until I removed it for the trans seal replacement.

I ordered the U joints this morning. Wish me luck.

i am not saying it is not oem...especially for the 80's.

well. like i mentioned previously only double cv i have seen were on diesel b2. but it was adouble cv...

they came that way far as i know. maybe my memory is off about them that was 30 years ago...but they had rectangle weights and a spicer style number....when i see shit like that i pay attention. these trucks were newer then...b2 drive shafts were already an established issue i was dealing with...plows are hard on stuff.


conversely...if gramps had an issue, and the word at the time had tales of a cure....and was told this was the fix...i do think he would have said fix it....if it happened during a certain period in the late 80's and early 90's there were all sorts of percieved issues with these and vibrations, and there are at least 9 different combinations that i know of just for the b2 from the oem.

so, i absolutely can believe this was a wasted attempt to fix something... you still sense while driving...and going to a single single might actually be a fix..


and i would not buy one fookin part until i absolutely pulled the shafts out and carefully assessed the condition of the joints. replacing good u joints with new u joints probably wont fix whatever is bugging you.


if thee are obvious bind issues then replacement has to happen.

 

[ford4wd08]

i am not saying it is not oem...especially for the 80's.

well. like i mentioned previously only double cv i have seen were on diesel b2. but it was adouble cv...

they came that way far as i know. maybe my memory is off about them that was 30 years ago...but they had rectangle weights and a spicer style number....when i see shit like that i pay attention. these trucks were newer then...b2 drive shafts were already an established issue i was dealing with...plows are hard on stuff.


conversely...if gramps had an issue, and the word at the time had tales of a cure....and was told this was the fix...i do think he would have said fix it....if it happened during a certain period in the late 80's and early 90's there were all sorts of percieved issues with these and vibrations, and there are at least 9 different combinations that i know of just for the b2 from the oem.

so, i absolutely can believe this was a wasted attempt to fix something... you still sense while driving...and going to a single single might actually be a fix..


and i would not buy one fookin part until i absolutely pulled the shafts out and carefully assessed the condition of the joints. replacing good u joints with new u joints probably wont fix whatever is bugging you.


if thee are obvious bind issues then replacement has to happen.

Understood on all of your comments.

I've ordered parts that I can easily return if need be.

I'll try to remove it again this evening and have a better look.

I know having such a short wheel base hasn't helped the BII in driveshaft department.

 

[ford4wd08]

Just another comment, I drove this Bronco for years as a Teenager with my grandparents. I don't ever remember it having any type of vibration or anything like I am experiencing.

The hardest thing on this rig was it sat for about 6 or 7 years on his black top driveway and wasn't driven.

That is why I am hopeful that rebuilding the driveshaft will help with the vibration issue. If it doesn't work, I'll move onto other options.

I'm not overly concern with dropping money into this rig (I know it is a terrible ROI). I plan to daily drive this rig and fix anything that needs it as I go. This way I can have a little piece of my granddad with me all the time.

Plus driving a '16 supercrew f150 gets old going to stores, fighting traffic, and fitting into parking spots. The BII is a sweet little rig for getting around and maneuvering anything!

 

[Shran]

Are you running the old tires that sat for 6-7 years?

I have a set of Cooper Cobras on my F150 that see maybe 2-300 miles a year and it sits in one spot virtually all the time. They absolutely develop flat spots and it shakes a bit until the tires warm up. Driven often, it's not an issue but when I pull it out in the spring after sitting for a few months it's pretty bad.

I also had a Crown Victoria years ago that shook really bad. The tires dry rotted from the inside somehow - tried having them balanced and they couldn't be... shop dismounted one and it was full of ground up rubber chunks. The other tires were like that too. They looked fine on the outside.

Worn out u-joints can certainly cause vibration, you'll get it figured out, just throwing some other ideas out there.

 

[ford4wd08]

Are you running the old tires that sat for 6-7 years?

I have a set of Cooper Cobras on my F150 that see maybe 2-300 miles a year and it sits in one spot virtually all the time. They absolutely develop flat spots and it shakes a bit until the tires warm up. Driven often, it's not an issue but when I pull it out in the spring after sitting for a few months it's pretty bad.

I also had a Crown Victoria years ago that shook really bad. The tires dry rotted from the inside somehow - tried having them balanced and they couldn't be... shop dismounted one and it was full of ground up rubber chunks. The other tires were like that too. They looked fine on the outside.

Worn out u-joints can certainly cause vibration, you'll get it figured out, just throwing some other ideas out there.

Yes, tires were my first thought for sure. They were brand new when he put them on and it parked.

I believe there is some flat spotting with them, but I don't believe that is the issue I'm fighting.

That is the reason I went and did the smooth pavement test. I could turn it on and turn it off by having the vehicle under load vs coasting. If it was the tires, I believe I would feel it all of the time.

But I will continue to work on it. New u joints certainly won't hurt anything.

 

[ford4wd08]

Covering this in a few different threads, don't know how I missed the page over on Bronco II Corral.

I'll post it here for reference. It has a picture of my style driveshaft in it.....

https://www.broncoiicorral.com/tech_library/bronco-ii-rear-driveshafts-pinion-angles/