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BN2 Transmission

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Bruce Bowker

Bruce Bowker

Obi Wan
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It looks like I will be having the trans taken out. Reverse and now 2nd gear will not stay enganged.

Any tricks, upgrades (seals?) or anything else one might recommend while it is out?

Also can just the trans be dropped or is it an entire engine removal?

Thanks for any help.

Bruce
 
Might want to get the O/D rebuilt while it's out or do the Toyota 5 sp. upgrade and keep the old one on the side...

Best of luck...

Michael.
 
Healeysince59 said:
Transmission can come out through the cockpit, I just did it.

Marv J
Click to expand...

Marv - thanks. Tunnel unbolts or it needs to be cut in any way?

Also somewhere in the back of mind, I recall a seal upgrade. Something had to be mildly machined and a much better seal put in??? Not sure if that was an AH or a Jag though or somne other car.

Bruce
 
Tunnel should come out with screws around the flange. Then there is a flat piece at the front of the tunnel that comes off next. I then rotated the transmission so the starter bulge in the bellhousing would come through the opening. It should be a 2 man job at this point but I did it alone - stupid.

Marv J
 
The BN2 has rubber seals on the back of the bellhousing/front of the transmission and at the rear of the O/D (you have to remove the yoke). Replace these while you're at it.

There is a rear main seal kit for the 100s, but you have to machine the crank and the rear main bearing so it's not an in situ install like it can be for the 6-cyl engines.
 
Marv, I recall reading some time ago that there is an upgraded front seal assembly for these transmissions.--Fwiw-Keoke
 
Bob_Spidell said:
The BN2 has rubber seals on the back of the bellhousing/front of the transmission and at the rear of the O/D (you have to remove the yoke). Replace these while you're at it.

There is a rear main seal kit for the 100s, but you have to machine the crank and the rear main bearing so it's not an in situ install like it can be for the 6-cyl engines.
Click to expand...
An original BN2, 100/6 or early 3000 xmsn would <span style="text-decoration: underline">not</span> have a front seal, just a reverse scroll on the inside of the cover.

IMG_7413.jpg


With the possible exception of the bellhousing bolt pattern, The BN2 is identical to my BN6 xmsn. There are numerous (hundreds, really) pictures available at the bottom of this page: https://www.rfdm.com/gallery/albums.php?set_albumListPage=12 Look in the sub-albums under <span style="font-style: italic">Healey at home</span>
 
Great ideas everyone and great pictures Randy. Thanks

Bruce
 
Welcome back to the forum, Randy.

Our BN2/100M has a front seal--I just replaced ours (the old one was extremely dry and brittle and leaking like a sieve--it may have been the original). It may be a fluke, or possibly someone modified it, but I used a Moss part that was was listed in older catalogs but isn't in the latest.

I was surprised that the BN1s and early sixes didn't have a seal, but the BN2 did. I'll do some more digging on this.
 
Moss lists a front seal for sideshift BN7, BT7 with a note that BN4 and BN6 models do not have replaceable first motion shaft seals. They don't mention BN2. My BN2 bellhousing has a seal and I used the Moss seal to replace it. I don't know if this is original or some PO machined the bellhousing for it.

The BN2 uses a mechanical clutch linkage and requires a completely different bellhousing than the 100-6. Original BN2 bellhousings are very scarce and precious.

Marv J
 
was surprised that the BN1s and early sixes didn't have a seal, but the BN2 did. I'll do some more digging on this.

Yep you are corect Bob.
I just located an old parts sales advertisement and the earlier cars were modified because the "Scroll" Labrinth seal would wear excessively and leak.--Fwiw--Keoke

For Sale:
BN2 Aluminum bellhousing is in perfect condition (just replace the seal) . :smile:
 
Healeysince59 said:
Moss lists a front seal for sideshift BN7, BT7 with a note that BN4 and BN6 models do not have replaceable first motion shaft seals. They don't mention BN2. My BN2 bellhousing has a seal and I used the Moss seal to replace it. I don't know if this is original or some PO machined the bellhousing for it.
Marv J
Click to expand...

Look at the bottom left corner of the Moss catalog page prior to the listing for the BN7/BT7 listing (page# 52 in the old catalog I checked). It lists a seal for the BN2 bellhousing, but "not illustrated." It's the same part# as for the later sixes.

Apparently, Austin added the seal for the BN2, then didn't add it for the first year or two after they went to the 6-cyl engine with hydraulic clutches, then re-added it with the BN7s and BT7s and thereafter.

Randy, have you rebuilt some BN2 transmissions that didn't have the seal?
 
If I am reading all this correctly, the BN2 does NOT have a hydraulic clutch? If it does have one, where is the reservoir?

Bruce
 
Marv - thanks. Things are definitely going south in the trans and clutch area.
 
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