As many of you know from my posts a few months back I am installing a rebuilt transmission in my '19 Touring that also has a Ruckstell rear end that was previously installed last year. While I had the engine and transmission out of the Model T and the rear end up on stands last week I noticed that if I turned the driveshaft by hand (no universal installed)I had about 1/4" of rotation at the drive shaft before a rear wheel would begin to turn. You can barely feel the meshing of the ring and pinion gears immediately when the shaft is turned and I set this area up myself so I do not believe the slack is in that area. I also noticed that when I manually turn a rear wheel by hand there is about 4 inches of rotation before the opposite wheel begins to move. The play noticed at the drive shaft and play between the rear wheels rotation leads me to believe the slack is in the spyder gear assembly. Any ideas? I doubt if this much slack is normal. Thanks....Michael Pawelek
You're right...sounds like your spiders have got troubles.
Could be spider wear, spider pinions worn, differential gears worn, case worn where spider fits in it, or a combination of all these by the amount of play you have. Anything that lets the spider pinions and differential gears to move away from each other will cause a lot of play with what doens't appear to be a whole ot of wear.
When I opened up my differential, I found that the bolts holding the spider in had come loose. Most of the pins holding the bearings/babbit washers had severed off. It wouldn't take much time to figure out what the problem is, if you open it up...
This differential unit was gone through and rebuilt by another experienced Model T'er and I only set up the ring and pinion mesh. He stated that another experienced Model T'er had done some of the work for him so considering "many" parties were involved with the rebuild it is not clear exacly what was done to the unit before it was sent to me. I am just curious as to whether there should be any slack movement between the rear wheels at all or if some is acceptable. I was changing a rear tire on a Ford 8N years ago and when the rear end was blocked up off the ground also noticed play between the rotation of the rear wheels. So on a properly rebuilt and fitted unit is any play between the movement of the rear wheels acceptable at all? Thanks...Michael Pawelek
Michael, it has been my experience there is some play between the axel gears and the spider gears. Over time the inner surfaces of the differential cage wear causing the axel gears to move outward. Ever notice how the disc placed inside the spider is never thick enough? It is normal to move a rear wheel some without engaging the drive line. Four inch movement at the tire wouldn't bother me.