Can't replace 27 spline washer?

[ericbphoto]

Thanks for pulling this all together in one post

 

[Shran]

IMO if you are running into very thin spacers, they were not originally that way and were worn down by riding against the spindle. They should be pretty thick.

I grab every single one of these and the C clips that hold them on when I'm at the junkyard. I can't tell you how many I've replaced, lots! It's a really stupid design. The older trucks had two flat thin washers and a bearing there, I almost never saw those fail.

Most people seem to just remove them entirely. I can't say whether I agree with that practice or not. Their purpose is partially to keep the U joint centered between the axle beam and knuckle and therefore preventing it from binding while turning in 4 wheel drive. I have never seen any damage result from not having the washers in place.

 

[lowspeedpursuit]

The thick and thin fully-splined washers are two different Ford parts, with the FOTZ and F57Z prefixes, respectively. The thin splined washers are part of a set that includes a plastic spacer and another thin, unsplined thrust washer.

In addition to my earlier picture that includes the stuff that originally came off my front axle (far left), you can see a picture of the three "thin-washer" pieces apparently sold together at these two NLA product listings:

https://www.amazon.com/Ford-F57Z-3B458-A-WASHER/dp/B000O0DDNW
https://www.fordpartsgiant.com/parts/ford-washer_f57z-3b458-a.html

I'm honestly not sure what the original difference in application was between the thick/FOTZ and thin/F57Z washers. My front axle donor vehicle and the D35 Ranger I found in a junkyard were both '93, but used different versions of the washers. My '94 service manual shows 1 part, not 3, on the exploded view, and refers to it as a "spacer". This is what Ford calls the FOTZ, while the F57Z is a "washer". I think this implies that thick/FOTZ was original equipment in '94, but I really can't be sure.

In any event, if the thin washers were subject to breaking, and only thick washers are available anymore, the difference at this point is entirely academic.

I wouldn't feel comfortable running without the washers because the D35 TTB inner axle shafts are, as far as I can tell, also NLA. It would suck to misalign the axle shaft, blow the u-joint, and potentially take out the ears on a shaft that can no longer be replaced.

 

[Shran]

Well, F0xx would have been a part introduced in 1990 and F5xx would be one introduced in 1995. Maybe they figured out that the early washer/clip setup is junk and revised it sometime in '95.

Like I said I have never seen anything other than one single thick spacer and one C clip, on everything from '90 up to the end of the TTB in 1997. My wife's '95 has that and so does the spare axle I have from a '97. But, I have certainly not seen every truck out there, and both of mine could have bene assembled from earlier parts. Hard to say!

 

[lowspeedpursuit]

Yeah, I'm not sure. The thought had crossed my mind that maybe Explorers got one washer and Rangers got the other, which could explain the 3rd prefix digit: T for truck (Ranger) vs not-T for the Explorer, but the basic prefix decoder doesn't explain what a number in the 3rd digit means. The 2nd digit in FOTZ appears for all the world to be the letter O, not zero, which is also unexpected, and obviously if the 5 in F57Z refers to 1995, it would make no sense for that to be an Explorer-specific part, since they only used the TTB through '94.

It would also be weird for the thick washers to be '90+ and thin '95+, since thin seems to be the inferior design since they keep breaking.

I've really got no clue.

 

[Shran]

I missed the letter O vs zero part. Not sure about that. Makes sense in my mind that O=1990 in this case because 1990 would be the first year that the D35 axle was used, thus the first year that the spacer was used was 1990.

Typo, maybe. No mention of the letter O: https://www.blueovaltrucks.com/tech-articles/how-to-decode-ford-part-numbers/

F0TZ = 1990 decade, 1990, Truck, Ford Customer Service Division (Ford), Product Analysis and Publications
F57Z = 1990 decade, 1995, Explorer/Ranger, Ford Customer Service Division (Ford), Product Analysis and Publications