aa-4645 aa-4655.... again! ARRRGH!

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Tim mc

aa-4645 aa-4655.... again! ARRRGH!

Post by Tim mc »

I think I might have isolated the problem with my dual high unit(s). The last two units I went through ran hot and toasted the bearings at the ends in short order. So, I figured the heck with it and ordered a jackshaft from Berts. Steve had an NOS one with NOS aa-4655's in it, along with a used shaft.

So I ordered that and this morning started assembling the new bearings I already had from Snyder's into the assembly. Problems right off.... the shaft won't slide into the bearings. After some work, got the shaft to slide into one and it did move, but with lots of force and was really rough. I slid and old bearing into the assembly, and it fit fine, but it's too pitted to use.

So I think the problem all aloing has been that the aa-4645 bearings that are available are the wrong ones... they fit too tight and cause friction and self-destruct too soon.

My next step is to call model A works or Tired truck to see if they have run into this problem. I"m thinking that the reason that the bearings 'fit' in the dual highs that I had was that the shafts on them were worn enough to allow it to fit, yet under load the clearances were still too tight and caused them to fail.

Does anyone know how to measure roller bearings like these?

Thanks!
Tim Mc
tim

coupling shaft

Post by tim »

hi was reading your problem on bearings did you work it out im looking for pic diagram to assemble my coupling shaft im rebuilding a 28 aa stake body looks like im where you were in may do you know any diagrams of 28 coupling shaft thanks
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Neil Wilson
Posts: 3062
Joined: February 5th, 2003, 9:42 pm
Body Type: 82-A/89-A
Model Year: 1930
Location: Boulder, CO
Contact:

Parts AA-4645/AA-4655

Post by Neil Wilson »

Hello Tim,
I have been looking at the Ford Parts Price Lists. It looks like the roller bearing and sleeve (AA-4645/AA-4655) were for the front of the AA drive shaft, the '28/'29 coupling shaft, and the dual high. So, any information found on these two parts would be of interest to all AA'ers.

It looks like the roller bearing is listed as AA-4645-A in the rear axle parts. The listing for the coupling shaft and dual high indicates to order AA-4645 in some of the earlier lists. Later list indicate to order AA-4645-A.

I believe that AA-4645 and AA-4645-A are one in the same.

This does not answere your question about how the measure the bearing. I would like to hear any more details regarding this subject.
Regards, Neil Wilson
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tiredtruckrestorer
Posts: 338
Joined: April 20th, 2003, 7:09 pm
Model Year: 1931
Location: Orwigsburg, PA

Post by tiredtruckrestorer »

Hello Tim,
I see you were going to contact me (Tired Truck) about your bearing problem. Since I did a seminar in Dearborn on the AA drivelines I have done a little research on this subject. I can offer this information. In a 4-3-31 Service Letter, the driveshaft roller bearing surface diameter is listed as 1.246-1.247. Up to .005 wear is allowed before the driveshft should be replaced. Since the same bearing is used in the dual high, I assume that the dual-high shafts should be the same diameter. Next, I measured the diameter of a roller on a new bearing and a used one. A used one measured .290 and a new currently available one measued .2925 which is a .0025 difference. I then took the bearings and installed them on a 28-29 coupling shaft. I rotated the bearings on the shaft and measured the maximum diameter needed to turn the bearing on the shaft with a calipers. I needed to rotate the bearings as the two bearings had different number of rollers. Both measured about 1.836. I had some AA-4655 bearing sleeves made up as a test with thoughts of reproducing this item. We determined that the sleeve inside diameter measured 1.845. That would give us a clearance of .009 which I believe should be enough. These are just my observations and measurements. It was kind of hard to get precise measurements of the bearing on the shaft as the rollers on the original bearing can really move around in the bearing cage that holds them together. Probably the best way to get the original measurements is to contact the Ford Archives to see if the drawings are available for those part numbers. I may follow up on this to see what I can find. Hope some of this makes sense and may help with your problem. Keith Ernst
Mark in Fairbanks Alaska

Dont Call Tom in Portland!

Post by Mark in Fairbanks Alaska »

Dont waste your time with the Model A Works in Portland. That guy is a thief and he doesent return calls or more likely wont answer his phone.
deeame

Model A Ford Works

Post by deeame »

:( I ordered the bearings for the worm drive for my early '29 AA last spring. He answered the phone and I had my bearings in about two weeks. This luck did not hold in early June. I called and he did return the call. I ordered the bushings for the rear springs. He said they would be ready in about 3 weeks (July 1). No bushings, I started calling to talk to an answering machine and no return calls. Finally in late September I sent a certified letter which was not picked up and was returned. :D Good news: The bushings arrived the same day as the returned letter. They are excellent quality and fit perfectly. :?: I do not understand why he has such pitiful customer relations. I would not call him a thief now but I called him much worst before I got the bushings.

Don
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