To replace a transmission input shaft seal does the rear crankshaft oil seal come into play 2001 bmw m roadster

red oil is transmission input shaft or torque converter seals
Transmission removal for the fix
rear main seal is black or engine oil color and is again transmission removal for fix
procedures are stated in the workshop manual for either or find an accredited service specialist shop with experience on your make of vehicle
looking at up to 8 hours labor time plus parts

There are seals on the front and rear of the transmission. If the clutch wasn't covered in engine oil, then replacing the crankshaft seal wasn't necessary. Reseal the transmission.

There are three different seal sizes 90mm shaft, 92mm shaft and 94.5mm shaft. Make sure you have the right seal for your crankshaft.

several things, the rear main seal is accessable by removing the transmission. if this vehicle is standard transmission, then would recomend new clutch at this time given the amount of labor involved. if automatic, remove drive shafts, transfer case, transmission, and flexplate ....replace rear main. approx 5 hrs.

DW Mylin

Dear Sir,
Here is the oil leaking Problem Identifying Technique

Engine oil leaks from the valve cover gasket are common.

The intake manifold plenum gasket may leak and cause increased oil consumption/burning and a spark knock during acceleration; the gasket should be replaced.

External oil leaks from valve cover gaskets, intake gaskets (front or rear), and the rear crankshaft (rear main) seal area are common. The rear main seal is an unlikely source. Normally, the bearing cap mating surfaces (as well as the sealing surface between the oil pan and bearing cap) are the source for the leaks.

Engine oil leaks at the distributor can be misdiagnosed as leaks from theintake manifold seal, oil pan gasket, or rear crankshaft (rear main) seal. A revised distributor is available if oil is found inside the distributor.

If the oil filter casing shows signs of distortion from excessive oil pressure, theoil pump should be replaced.

Often misdiagnosed as a leaking oil filter gasket, the oil filter adapter can seep from between the adapter and engine block.

Carbon buildup on the top of the piston is common. As the buildup increases with mileage and over time, symptoms may vary from light ticking, to ticking/hammering, to hammering/knocking noises. Fuel injector cleaner often solves the problem.

I think it helps to analyse u r Problem

YOU NEED TO REMOVE FLYWHEEL REMOVE OIL PAN. REMOVE REAR OIL SEAL HOUSING BOLTS. USING THE PRY POINT LOCATED AT THE EDGE OF THE CRANKSHAFT REAR MAIN SEAL HOUSING SHEAR THE RTV SEALANT. REMOVE THE REAR MAIN OIL SEAL. INSTALL GUIDE PINS INTO THE TWO CRANK SHAFT REAR OIL SEAL HOUSING CORNER BOLT HOLES OF THE ENGINE BLOCK.INSTALL THE CRANKSHAFT REAR SEAL INSTALLING TOOL ONTO THE REAR OF THE CRANKSHAFT FLANGE. APPLY A 0.2 INCH 3MM BEAD OF SILICONE SEALANT TO THE REAR OIL SEAL HOUSING . INSTALL THE REAR HOUSING TO THE ENGINE BLOCK.REMOVE THE GUIDE PINS AND INSTALL THE HOUSING BOLTS TIGHTEN THE BOLTS TO 89 INCH LBS. REMOVE THE REAR SEAL INSTALLATION TOOL FROM THE CRANKSHAFT FLANGE.THEN INSTALL OIL PAN AND FLYWHEEL.

I'm not sure if this is the right part of your car but, are you talking about the rear seal on the engine for the crankshaft?

If so:

Rear Main Oil Seal REMOVAL & INSTALLATION Fig. 1: Rear main seal installation for the 2.3L and 2.5L engines
Fig. 2: Removing the rear main seal
Fig. 3: Installing the rear main seal on the 2.9L engines
If the crankshaft rear oil seal replacement is the only operation being performed, it can be done in the vehicle as detailed in the following procedure. If the oil seal is being replaced in conjunction with a rear main bearing replacement, the engine must be removed from the vehicle and installed on a work stand.

1. Remove the starter.
2. Remove the transmission from the vehicle, following the procedures in Section 7.
3. On a manual shift transmission, remove the pressure plate and cover assembly and the clutch disc following the procedure in Section 7.
4. Remove the flywheel attaching bolts and remove the flywheel and engine rear cover plate.
5. Use an awl to punch two holes in the crankshaft rear oil seal. Punch the holes on opposite sides of the crankshaft and just above the bearing cap to cylinder block split line. Install a sheet metal screw in each hole. Use two large screwdrivers or small pry bars and pry against both screws at the same time to remove the crankshaft rear oil seal. It may be necessary to place small blocks of wood against the cylinder block to provide a fulcrum point for the pry bars. Use caution throughout this procedure to avoid scratching or otherwise damaging the crankshaft oil seal surface. To install:
   
6. Clean the oil seal recess in the cylinder block and main bearing cap.
7. Clean, inspect and polish the rear oil seal rubbing surface on the crankshaft. Coat a new oil seal and the crankshaft with a light film of engine oil. Start the seal in the recess with the seal lip facing forward and install it with a seal driver. Keep the tool, T82L-6701-A (4-cyl. engines) or T72C-6165 (6-cyl. engine) straight with the centerline of the crankshaft and install the seal until the tool contacts the cylinder block surface. Remove the tool and inspect the seal to be sure it was not damaged during installation.
8. Install the engine rear cover plate. Position the flywheel on the crankshaft flange. Coat the threads of the flywheel attaching bolts with oil-resistant sealer and install the bolts. Tighten the bolts in sequence across from each other to the specifications listed in the torque chart in this section.
9. On a manual shift transmission, install the clutch disc and the pressure plate assembly following the procedure in Section 7.
10. Install the transmission, following the procedure in Section 7.

yes , depending on wheter you talking about torque converter seal or rear engine main seal , on trans if your front pump bushing has excessive wear then it will not seal because the torque converter input shaft will ride on seal more than it is supposed to and also it will not run true, also check TC mounting of flex plate if you flex plate is not centered then it will rotate out of balance and cause leaks and pump damage, if you talking about a rear main engine seal you may have a issue with run out and or bearing wear issues cause seal to not be able to do its job, check all those issues, crank shaft end play as well as up and down play and check rotational run out on TC of trans and pump bushing in trans pump... hope this helps, thanks please rate...

There are only two paths for oil there. The rear main, and a oil galley plug a little higher up, about 2 o'clock.

there ar two oil seals on your vehicle one is located behind crankshaft pulley and the other is located at rear input shaft to transmission you will need to remove your crankshaft pulleys including pulley boss or transmission and flywheel and torque converter if automatic to change seals are fairly cheap and easy to remove just follow steps in repair manual from local parts store. Or take it to a shop lol.