Rubber seal around gearbox?

[John Loftus]

I was reading in Geoff Healey's book about the proposed and actual changes for the BJ7 model. He said that, "Hot air from the radiator and power unit was flowing through the space between gearbox and tunnel. This was reduced by the use of a rubber seal around the gearbox to engine joint."

Can anyone describe this part, how it was attached and/or have a picture? I can't find it in the BJ7/8 Parts book. Perhaps it was never produced?

The BCS catalog has a heat deflector which is the closest thing I've seen but it says it's for "all side shifts".

Thanks,
John

 

[Dave Richards]

Having just tackled this problem on my BJ8, I can offer an opinion.

The Moss catalog shows these seals on the Miscellaneous Trim Fittings page for some models of BN7 and BT7 and for all BJ7's and BJ8's, but does not offer them, they are shown with the gearbox covers.

When I asked what other BCF members used, several folks responded by showing pictures of various weather-stripping, and foam tapes used to seal caps to pick-up truck beds, one person also suggested silicone, which would also provide a very good seal, but would have to be reapplied each time the cover was removed.

I only needed to replace the seal on the drivers side and at the front and rear of the tunnel. The original seal on the passenger side could be described as a closed cell rubber foam strip.

I purchased a 3/4" x 1/4" self adhesive weather-stripping from a True Value hardware store. This material seems to closely approximate the size and shape of the original material, although it is not as dense. The strip was applied to the vertical portion (or lip) of the floor board that the gearbox cover fits over.

The tape is also applied to the front of the tunnel, which seals against the carpet on the bulkhead, and to the underside of the fiberglass tunnel at the metal driveshaft tunnel.

I have reinstalled the gearbox cover and am very happy with the fit.

I originally removed the cover to make an inspection and apply heat shield material to the cover, this is adequately covered in other threads, try "gearbox cover", or the like.

I had a very steady stream of scorching air entering the driver's side of the tunnel before removal and upon inspection could see why, the seal was mostly gone. This should make an appreciable difference.

 

[John Loftus]

Hi Dave,

I'm aware of the gearbox cover seals along both sides, front edge and over the rear part of the drive shaft tunnel. I was visualising something different when reading the words, "rubber seal around the gearbox to engine joint". To me, this describes a large seal that reduces the motor/radiator heat from entering the gearbox area. Maybe they never made a piece like this for the BJ7/8. The sketch from the BCS catalog looks like a sheetmetal and rubber assembly that would fit in the firewall tunnel opening. I'll give BCS a call unless someone else knows what I'm describing.

Cheers,
John

 

[Ed_K]

John,
Let us know if there is such a thing. It sounds like a good idea to install if one exists.
Ed K.

 

[Keoke]

HI John I do not know of any way to prevent Engine heat from entering the gear box area. The seals you mentioned are all the seals used on the car. Actually IMOP the heat conducted from the engine to the gear box can not be attenuated. Similarly, the gear box itself is a hot runing item having the OVD pump producing 490 PSI oil pressure.--Fwiw--Keoke-?

 

[Dave Russell]

I was reading in Geoff Healey's book about the proposed and actual changes for the BJ7 model. He said that, "Hot air from the radiator and power unit was flowing through the space between gearbox and tunnel. This was reduced by the use of a rubber seal around the gearbox to engine joint."
Thanks,
John

Hi John,
My BN2 still has the original seal/heat deflector. You can see it here as iitem 7. Although listed as NA.
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=28963&SortOrder=9

As to how well it works, It DOES keep the engine & exhaust heat from fflowing back into the transmission tunnel. It might actually make the transmission cooler since the engine & exhaust heat which is far hotter tthan the transmission is somewhat blocked.

Basically it is a rubber flap about 1/4" thick that is riveted to the extension panel & fits snugly around the front of the transmission.

Attached is a pic of the panel & seal viewed from the engine side.
D

 

[John Loftus]

Hi Dave,

Thanks for the photo and description. Maybe this was one of those items they wanted to add to the 6 cylinder with the introduction of the BJ7 but was crossed off the list? I'll dig around some more ...

Cheers,
John

 

[tahoe healey]

It looks like something that could be made form an old inner-tube???

 

[Keoke]

Hi Dave,

Thanks for the photo and description. Maybe this was one of those items they wanted to add to the 6 cylinder with the introduction of the BJ7 but was crossed off the list? I'll dig around some more ...

Cheers,
John

Thank goodness for that oversight. INMOP all this would do is add to the existing static pressure under the bonnet potentially increasing engine temps. Perhaps this is why the 100's seemed to favor the bonnet louvers.---Keoke-?

 

[John Loftus]

It looks like something that could be made form an old inner-tube???

Perhaps but I think most inner-tube is thinner than 1/4" and probably too flexible for this application (needs to be stiff enough to hold shape at highway speeds) but rubber and synthetic rubber materials are available in sheet form (McMaster Carr being one place to get smaller quantities). This would be one of those experiments where a couple heat sensors in the tunnel and engine compartment both before and after installing a baffle would be required to see the effect in different driving and idle conditions. Otherwise we are just speculathesizing. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif (not that there's anything wrong with that!)

 

[Dave Richards]

Would the transmission greatly benefit from the cooler temperatures the shield shown in the photos might produce?

Wouldn't a heatshield on the underside of the tunnel be a good compromise?

 

[Keoke]

Wouldn't a heatshield on the underside of the tunnel be a good compromise?

No Dar100, because the heat shields you have seen added to the underside of the tunnel are provided to keep the heat inside the tunnel and out of the cockpit.---Keoke

 

[Dave Richards]

Wouldn't a heatshield on the underside of the tunnel be a good compromise?

No Dar100, because the heat shields you have seen added to the underside of the tunnel are provided to keep the heat inside the tunnel and out of the cockpit.---Keoke

Would the transmission greatly benefit from the cooler temperatures the shield shown in the photos might produce?

 

[GregW]

Hi John,
OSH usually has a variety of rubber and neoprene sheets. Mine stocks them under the cutting table near the rope section. Just in case you want to touch it before you buy.

 

[John Loftus]

Would the transmission greatly benefit from the cooler temperatures the shield shown in the photos might produce?

Hi Dave,

Greatly benefit? I doubt it. Seems like the gearboxes and OD's are pretty robust considering how many are still functioning well after 40-50 years and will run all day long without problems. Might be a benefit in a really hot climate but then you have to wonder if it will block some flow of air from the engine compartment and raise engine temperatures? It does seem like it would reduce the temps trying to blow past the tunnel seals into the interior. Ever notice how hot the ash tray, gear lever and e-brake handle get on a long drive? But I'm just specula-thesizing since I don't have data to back up the ramblings. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

 

[John Loftus]

Hi John,
OSH usually has a variety of rubber and neoprene sheets. Mine stocks them under the cutting table near the rope section. Just in case you want to touch it before you buy.

Hi Greg,

Good to know .. especially for other more pressing projects!

 

[Keoke]

Wouldn't a heatshield on the underside of the tunnel be a good compromise?

No Dar100, because the heat shields you have seen added to the underside of the tunnel are provided to keep the heat inside the tunnel and out of the cockpit.---Keoke

Would the transmission greatly benefit from the cooler temperatures the shield shown in the photos might produce?

Perhaps if that were the only heat source for the transmission the shield might produce cooling that would benefit the Transmission. However, if you really want to reduce the temperature of the air in the tunnel you need to attack the source. Cooling the source requires getting the hot air out of the engine compartment as fast as possible. Historically, this has been done in the cars using bonnet louvers or fender vents. In the 3000 coupe produced in the 60's very attractive fender vents were installed while the bonnet louvers were most often seen. Therefore, IMOP building an air dam around the engine is not conducive to significantly reducing transmission operating temperatures.---Fwiw-Keoke

 

[Dave Richards]

Probably why it didn't carry over to the sixes...

 

[Rob Glasgow]

Not sure when they stopped installing the metal/rubber sheild, but my 1960 BT7 has one. As far as a heat reduction device, I'm not sure what effect it has. My car seems to produce am more than I care for. But then again, I don't think central California was the target market for the orginal designers....

 

[Johnny]

My '60 BN7 had one fitted from the factory to the shield secured by rivets. Some of which actually were still intact. I purchased a replacement from Moss and secured it with rivets. The rubber deteriated before I even installed the engine and I found it laying on the garage floor.
I made one from an old inner tube and it worked just fine, and is still on the car.
This item I feel is similar to the top, it's only meant to be used when the car is stopped, and in this case with the engine running it should reduce cockpit heat. In particular at the corners where the shield meets up with the bulkhead where supposedly you have a tight seal to the carpet.