Polyurethane bushings

[bluef250]

First, has anyone installed polyurethane suspension bushings? If so, how have they held up? Even if your truck sits for extended periods? What brand did you use? How long have you had them?

Secondly, the Prothene web site and other vendors give a part number for a F250 axle pivot bushing, then say "EXCEPT H/D."

1965 - 1979 Ford F250 & F350 2wd (with twin I-beam Exc. H/D).

I assume that means heavy duty. How do you know if you have a heavy duty axle? Except by pulling it apart and seeing if the part fits. The Ford manual says they used 5 different axle ratings on the 1968 F250. I think mine is the middle one. The brakes on the axle are 2-1/2" by 12" if it makes any difference.

[FORDification]

Polyurethane and polygraphite suspension bushings will definitely stiffen up the feel of the truck. Polyurethane tends to squeek and can be annoying, but polygraphite bushings are impregnated with graphite which acts as a lubricant to minimize the squeek. I'm using the polygraphite pieces from PST...in fact, I got their entire front end kit, which included the bushings and all new steering components. It'll be a while before I can give a first-hand account as to their performance, however.

When they're referring to the 'heavy duty' axles, it's not meant as a reference to the size of the axle pivot bushings or brake shoe size, but an increase in kingpin diameter. The axle rating should be stamped on the VIN tag on the driver's door and can be compared to the ratings on the pages on this site with the VIN data (links at the top of this page). However, I'm not entirely certain how to correctly determine kingpin size without actually removing and measuring one....but if your truck's rating isn't the highest on the list, I'd venture a guess that you might not have the heavy-duty version.

[NM5K]

I've found that "H/D" config for the 300 engine to be pretty confusing. I read once somewhere to what that meant extra, but I forgot...
Kinda surprised to hear about five different GVWR ratings among just the F-250, but anything is possible..I only knew about three, and the 68 brochure I have states 3 ratings. Maybe they had some others for other uses?? In the 68 brochure, they state 6100, 6900, and 7500 lb versions for the f-250..It states the 6900 and 7500 versions required HD brakes. No mention of kingpin dia, but it wouldn't surprise me if they were different. The only thing....When I bought new kingpins, I just stated the model and year, with no mention of the GVWR, and I got the correct ones. That almost leads me to believe all F-250's had the same kingpins, being mine is the heaviest 7500 version. I didn't order any "special HD" dia pin, but who knows, maybe they do have more than one size, and I just got lucky.
That brings up the pivot bushings...Again, I have the heaviest version f-250, but I bought plain jane stock pivot bushings. Again, as far as I've heard, there is only one size bushing for all. No one ever asked me if I had a HD version, and in fact, when people ask me that at parts stores, I say no. So far, saying no has gotten me the correct parts...BTW, it says on the VIN plate on the door what the GVWR is...Think it's on the left or left lower corner...
I think mine reads 07500 with a beginning zero, if I remember right. As far as the bushings holding up, I couldn't say. Mine are all stock type... But I haven't really heard any complaints of them falling apart..They are a bit stiffer than stock, in general. MK

[Rockcrusher]

I've never installed poly bushings in a 2WD but I have installed them in the 4 early Bronco 4WD's I've owned over the years. You will probably notice a little added harshness in the front end but at the same time there will likely be a noticeable improvement in handling.

[bluef250]

I got out the Ford Manual and this is what I found. I was mistaken. , there are 3 GVW for the F 250 and 6 different Codes.
Six model codes for F250 4x2

Code G.V.W. Dana 60 Rear CalcFront
F-250 7,500 5,500 2,000
F-252 7,500 5,500 2,000
F-253 6,100 5,500 600
F-254 6,900 5,500 1,400
F-255 6,100 5,500 600
F-256 6,900 5,500 1,400

At least two different rear axles brakes were used - one with 2 ½" shoe and one with a 2" shoe.

Rear Axle Codes

24 Dana 60 4.10-5.2M 4x2 4x4 F250
25 Dana 60 4.56-5.2M 4x2 4x4 F250

37 Dana 60 3.54-5.2M 4x2 4x4 F250
38 Dana 60 3.73-5.2M 4x2 4x4 F250

B4 Dana 60 4.10-5.2M Locking
B5 Dana 60 4.56-5.2M Locking

C5 Dana 60-2 4.10-3.6M

C7 Dana 60 3.54-5.2M Locking
C8 Dana 60 3.73-5.2M Locking

E5 Dana 60-3 4.10-3.6M Locking 100 4x2 opt 4x4 ltd slip F100
E9 Dana 60-3 3.54-3.6M Locking 100 4x2 opt 4x4 ltd slip F100

Four model codes for F250 4x4

Code G.V.W.
F-266 6,800
F-252 7,700
F-253 6,300
F-254 7,700

[bluef250]

I had a sales person from Pacific Automotice & Performance Center give me this information. Ben Sayles said, "It took some searching but I think we found a way for you to tell. You need to measure the outside diameter of the axle bushing on the truck. It should either be 1.86" or 2.10"." I assume that the H/D is 2.10" and regular (normal) is 1.86".

When I was researching spindles for putting disc brakes on my trucks, I found that several king pin diameters were listed in the parts books. When I asked, the parts person said the diameter is a function of manufacturing and quality control process, not related to load capacity. Might have been two or more suppliers. Or bad parts that were remanufactured by Ford, or Ford provides/suggests the larger king pins when machine work is done.

[FoMoCo]

Check out MOOG. They have blue urethane bushing kits. I know you wouldnt think of MOOG. I installed their radias arm bushing kit on my 93 Lightning and was happy with the results and prices.

Nick Wilson

[FORDification]

...When I was researching spindles for putting disc brakes on my trucks, I found that several king pin diameters were listed in the parts books. When I asked, the parts person said the diameter is a function of manufacturing and quality control process, not related to load capacity. Might have been two or more suppliers. Or bad parts that were remanufactured by Ford, or Ford provides/suggests the larger king pins when machine work is done.

Hmmm....I don't think that's accurate information you were given, from what I've found out through my research. Here's the table I put together based on that research (and posted to the Installing Disc Brakes on Your 2WD Pickup):


I spent a quite a while going through an auto parts store's books and this was what I was able to come up with. Compare, for example, the kingpin sizes for a '71 F-250 based on the various GVW ratings and brake type/size. I'll have to do some more poking around, but I'm 99.9% sure that Ford did indeed increase kingpin size with the heavier GVW trucks.

[bluef250]

Keith, I see significant differences between the axles/GVW and king pins. I think that you are right. These obviously are not supply or manufacturing changes and are related to vehicle GVW. I wonder what changes occurred during the manufacturing (drum vs. disc and serial M00,001) and if the increased king pin size is related to the engine size. The 460 cid engine is heavier than the FE series. Therefore the front end would need more “beefâ€Â

[FORDification]

...The changes in king pin size would also mean the I-Beam and spindles would not interchange freely between years.

I've been telling this to people for a while now, but I still run across people on 'other' Ford pickup forums stating that they will. In addition to the differences in kingpin diameter and length, there's also a difference in I-beam construction throughout the years, meaning that even if you mated a spindle and I-beam with similar kingpin sizes but from different years, you might still end up with a problem with the truck's turning radius, based on differences in how the steering bump stop was incorporated. I discussed these differences on the Comparing I-beams and spindles page.

Basically, when upgrading to disc brakes, it's a WHOLE lot easier in the long run to just use the entire front end from the donor truck....brakes, steering and suspension. It all bolts right up and alleviates any headaches down the road with incompatible parts.

[bluef250]

My brother converted a ‘69 F 100 LWB to 3/4 ton with disc brakes. I was surprised that the frame appears to be the same as my 68 F 250. I think he ended up using the I-beams and spindles from an E 250. After several attempts at mixing parts, he got everything from the E 250. He still had to “adjustâ€Â