Rear Main Seal Install Tool

[Crickett]

Hello, Family! When replacing the rear main seal, I understand this special install tool (p/n 83300490729) is intended to press the seal to the proper depth in the housing, but how vital is the install depth that a ~$110 tool is required?
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I’m gearing up to have a shop replace my clutch and the RMS and I’d much rather buy just the $15 seal itself but a bit worried whether the shop—whose mechanics I know to be skilled and competent, just not overly familiar w/BMWs—would get it installed correctly in the existing housing. I know the ~$120 full kit with the seal pre-installed in a new housing would prevent the issue, but at 10x the cost!

Alternatively, is there anyone in the Family that has the tool and is willing to loan it out? Or, if I bought it, is there enough demand for it to be put to good use more than the one time (I hope) I’ll use it?

[Pilot05]

No. Just use the cheap white donut-like installation tool that comes with most, new rear main seals.

Make sure you also use thread sealant (not locker) on the two larger bolts at the bottom of the RMS housing.

[Crickett]

No. Just use the cheap white donut-like installation tool that comes with most, new rear main seals.
From reading install instructions & DIYs (TIS, FCPEuro, E46f, etc.), I came away with the understanding that the white donut is to install the RMS (in the housing) on the crankshaft without the inner lip deforming, bending, ripping, etc. but this tool (or something else? Just careful, steady hands?) is required to install the RMS in the housing in the first place without the outer lip deforming, bending, ripping, etc.. In other words—assuming you have a RMS not pre-installed in a new housing—the steps are 1. Install the RMS into the housing using the above tool (having temporarily removed the white donut first). 2. Install the RMS-and-housing assembly onto the crankshaft w/the white donut. 3. Remove white donut and install bolts.

If I’m missing something, let me know, especially if you’ve done this maintenance!

[sillieidiot]

From reading install instructions & DIYs (TIS, FCPEuro, E46f, etc.), I came away with the understanding that the white donut is to install the RMS (in the housing) on the crankshaft without the inner lip deforming, bending, ripping, etc. but this tool (or something else? Just careful, steady hands?) is required to install the RMS in the housing in the first place without the outer lip deforming, bending, ripping, etc.. In other words—assuming you have a RMS not pre-installed in a new housing—the steps are 1. Install the RMS into the housing using the above tool (having temporarily removed the white donut first). 2. Install the RMS-and-housing assembly onto the crankshaft w/the white donut. 3. Remove white donut and install bolts.

If I’m missing something, let me know, especially if you’ve done this maintenance!
You are correct. Donut is when it's already in the housing ready to install onto the engine block.

I mean it would be better to have the tool. But I don't think you really need it. You could fab up something to just hit it to get it in there evenly.

I feel like most of us won't use the tool. I'd just buy the kit lol Because it comes with the gasket, crankshaft seal already installed in brand new housing, new bolts. Sure, it's more expensive, but if I'm doing that shit, I'm only doing that shit once. I don't want to do it again cause iono, I damaged the housing while uninstalling/reinstalling the seal and not know it or something lol

[Pilot05]

Yeah I have installed rear main seals on m54’s a couple of times..

Buying the seal already in the housing is a good way to go, but I usually tap a new seal into an existing carrier slowly/carefully with a block of wood as shown in one of 50’s kid videos.. as long as it’s even in the carrier, and not in the exact position of the old seal (and not proud of the carrier rim) you are likely okay.

Yes the white donut is for proper installation on the crank.. I mis-read your orig post.