84 318i pinion-bearing preload ???
- Thread starter Rukus
- Start date
The pinion is ajusted in & out with shims. This adjustment is for gear depth alone. Backlash is adjusted by moving the carrier side-to-side. If the pinion bearings are worn, the front one usually gets the most wear, it's time to replace all the bearings & seals. A trick is to buy two of the bearings where the shims go behind it. Have one bearing honed out where it just slips over the pinion shaft. This allows you to remove the bearing & add/remove shims without having to press the bearing back off.
Setting up a ring & pinion isn't difficult at all once you know what needs to be done. Having a press with a bearing splitter helps a bunch too....
Start with the housing & parts clean. New carrier bearings installed before setting pinion depth. Shim the pinion close to what the old one was or if your starting with a clean slate, just add about 35 thousanths. This is where the "oversized" bearing comes in handy. Have the housing with pinion side down, like a bowl. Install the pinion & yoke with a non-locking nut just to add some tension to hold the pinion in place snug. Seal shouldn't be installed yet. Install the carrier into the case. Run it over to the pinion with the threaded adjusters like a Ford 9 inch or a GM Corp 14, others use this same carrier bearing backlash adjustment, some use shims, which are the most fun because the case has to be spread apart with a spreader tool. Anyway, once you've adjusted the carrier over to where a slight backlash is felt by turning the pinion yoke back & forth very slightly. It's time to find out where the pattern is or how far the pinion teeth are in the ring gear teeth. Yellow oil paint, same as artist use to oil paint with works pretty good. Dab some on a four or five teeth of the ring gear. Turn the pinion with one hand while holding some tension on the ring gear to add some drag, this will help squeeze out the paint & show up better where the teeth are contacting. Look at the wear pattern, is it more twards the outer-side of center? If it is, your ok & ready to assemble. If the wear pattern is more twards the inner side of the ring gears teeth, some shim needs removed, "pinion depth is too deep". DO NOT INSTALL the honed out bearing. Once pinion depth is set, it can be installed correctly. A correctly se- up pinion will have 15 inch pounds of drag. Timken bearings should be tight but not too tight. 15 inch pounds has a slight drag feeling, shouldn't spin freely. With seal installed, additional drag will be felt. There are webb sites that show ring gear wear patterns if you'd rather see a picture of what they should look like. Heel patterns, there's nothing you can do if the load side pattern is correct and the heel side is not where it's suppose to be. Just don't hammer it in reverse is what I was told in class... for what that was worth. Back to setting carrier backlash. A standard transmission needs more backlash then an automatic. Some people just go by feel to set this. If you have a dial indicator with a mag base, great. set the indicator somewhere on the ring gear so when it's moved you can read the dial & see how many thou your at. Standards like about 4 to 5, auto's like about 3-4. Backlash has nothing to do with pinion depth. Moving the pinion in & out doesn't affect backlash until half an inch or so. We American's rarely get to see 140mph on the road so the 2.73-1 gears are a bit tall for us. I wouldn't go lower then a 3.42-1. Back in the early hot-rod days a 4.11-1 was the shit. With 1st gear being on the low side, 3.30-1 would be more reasonable, really it's what options you have the the first place if your thinking of swapping gears. Just remember 2 series are high, 3 series are reasonable, 4 series are low. Food for thought, a 3.08-1 is what I call a highway gear. 3.42-1 is the best for how I drive. 3.90-1 is damn near a drag race gear and too low for the highway if you travel much.
Hope this isn't too long winded. I haven't looked to see what gears are available for my car but I do plan on changing the ring & pinion on my car when I have it out to rebuild the sub-frame.
Setting up a ring & pinion isn't difficult at all once you know what needs to be done. Having a press with a bearing splitter helps a bunch too....
Start with the housing & parts clean. New carrier bearings installed before setting pinion depth. Shim the pinion close to what the old one was or if your starting with a clean slate, just add about 35 thousanths. This is where the "oversized" bearing comes in handy. Have the housing with pinion side down, like a bowl. Install the pinion & yoke with a non-locking nut just to add some tension to hold the pinion in place snug. Seal shouldn't be installed yet. Install the carrier into the case. Run it over to the pinion with the threaded adjusters like a Ford 9 inch or a GM Corp 14, others use this same carrier bearing backlash adjustment, some use shims, which are the most fun because the case has to be spread apart with a spreader tool. Anyway, once you've adjusted the carrier over to where a slight backlash is felt by turning the pinion yoke back & forth very slightly. It's time to find out where the pattern is or how far the pinion teeth are in the ring gear teeth. Yellow oil paint, same as artist use to oil paint with works pretty good. Dab some on a four or five teeth of the ring gear. Turn the pinion with one hand while holding some tension on the ring gear to add some drag, this will help squeeze out the paint & show up better where the teeth are contacting. Look at the wear pattern, is it more twards the outer-side of center? If it is, your ok & ready to assemble. If the wear pattern is more twards the inner side of the ring gears teeth, some shim needs removed, "pinion depth is too deep". DO NOT INSTALL the honed out bearing. Once pinion depth is set, it can be installed correctly. A correctly se- up pinion will have 15 inch pounds of drag. Timken bearings should be tight but not too tight. 15 inch pounds has a slight drag feeling, shouldn't spin freely. With seal installed, additional drag will be felt. There are webb sites that show ring gear wear patterns if you'd rather see a picture of what they should look like. Heel patterns, there's nothing you can do if the load side pattern is correct and the heel side is not where it's suppose to be. Just don't hammer it in reverse is what I was told in class... for what that was worth. Back to setting carrier backlash. A standard transmission needs more backlash then an automatic. Some people just go by feel to set this. If you have a dial indicator with a mag base, great. set the indicator somewhere on the ring gear so when it's moved you can read the dial & see how many thou your at. Standards like about 4 to 5, auto's like about 3-4. Backlash has nothing to do with pinion depth. Moving the pinion in & out doesn't affect backlash until half an inch or so. We American's rarely get to see 140mph on the road so the 2.73-1 gears are a bit tall for us. I wouldn't go lower then a 3.42-1. Back in the early hot-rod days a 4.11-1 was the shit. With 1st gear being on the low side, 3.30-1 would be more reasonable, really it's what options you have the the first place if your thinking of swapping gears. Just remember 2 series are high, 3 series are reasonable, 4 series are low. Food for thought, a 3.08-1 is what I call a highway gear. 3.42-1 is the best for how I drive. 3.90-1 is damn near a drag race gear and too low for the highway if you travel much.
Hope this isn't too long winded. I haven't looked to see what gears are available for my car but I do plan on changing the ring & pinion on my car when I have it out to rebuild the sub-frame.
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