I am trying to rebuild the rearend on my 25 coupe after 3 teeth broke off the pinion gear. I have both the 25 rear end and a 1910-21 rearend with the stud type pinion bearing. I will be buying the new style/modern bearing set up for it and I have several questions! First, is there any advantage of one style over the other except for bearing price? After I install the new style bearing do I have to replace the front bushing-both of mine are in good shape-is the needle bearing worth it and is it greaseable? They also offer a bearing with the shim kit to set pinion depth. Should I use this with a slightly worn ring and pinion that I have? The ring gear is slightly worn at the outside edge due to the common failure of the thrust spacer, but I think that when the gears are back in proper mesh this won't be much of a problem other than a bit of noise. This car was my grandfathers and is unrestored and is just driven once in a while. As a side note, my dad thinks he probably chipped one of the teeth 40+ years ago in upstate NY, when he used the T to pull a neighbors modern car out of a snowy ditch!! It started making noise afterward so he added STP which helped! I am a new member, and have enjoyed reading this forum! Thanks in advance!
Bill my recommendation would be to replace the pinion gear and the thrust washer after machining it the same thickness as the old one. I wouldn't replace either the roller bearing or ball bearing thrust washer. Keep it original. I did that on a car and it ran quiet with no drag. You have an original unrestored car; why muck it up? That's my opinion.
Richard, I forgot to mention that the pinion bearing on both rear ends are totally shot. They fell apart in pieces when I took them apart. The 25 outer shell is in good shape with no pits but the earlier one which has the replaceable bearing race has a very bad race in it. Since the general consensus of this forum in the past is that the new bearings don't hold up well in the pinion I figured it would be better to go with the modern bearing. Also, I live in the hilly south west section of Indiana and it puts a good bit of strain on the drive train!
I also have another question as to the carrier side thrust bearings-Brass or the needle roller bearings? The thrust bearings were replaced with brass back in the mid 50's by my dad for my grandfather while he was still using it as a daily driver. Dad is a mechanical engineer, and was working at Cummins diesel at the time, and made them out of brass, since new ones were impossible to find then.
My company is the maker of the pinion bearing kits that are sold by many of the dealers and also are available at our web site (www.funprojects.com). To answer your questions. The pinion bearing kit that we sell comes in 2 versions having ONLY to do with the mounting of the bearings. The kits are virtually functionally identical but in the case of the 09-21 spool housing, we have to put a sleeve into it first in order to mount the bearings. The later spool (22-27) does not need that sleeve and thus that kit is slightly cheaper. Both of these kits come in optional "adjustable" form to allow you to move the pinion gear in or out from "stock" position to thus improve the mesh if needs be but be advised that even our NON adjustable model is about 4 times more accurate than original setup with regards to pinion gear location positioning. The non-adjustable version will place the pinion gear in exactly STOCK position. We do NOT recommend using a needle bearing in place of the stock bushing at the top end of the driveshaft but we do recommend that you change that bushing from babbit to bronze if you still have a babbit bushing in there. In fact good mechanical engineering dictates that one should NEVER try to mate a hard bearing (the needles) with a soft shaft (driveshaft) since the thing that will wear out is the shaft and that is NOT desirable. Better that the bushing wears out but in truth there is very little load on that end of the drive shaft and bushings there seem to last almost indefinitely if you give them at least a small shot of lube now and then. I have over 40,000 miles on the upper bushing in my drive shaft on my "driver" '23 and it is still just as tight as ever. No signs of looseness. Bushings also run quieter than do bearings.
Hope this helps answer your questions.
You can download the instruction sheets for any of our products from out web site so feel free to download and read the installation instructions for the bearings so you can see how easy they are to setup. There are over 1500 of them in the field now. The first one is in my '23.