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Tranny Tunnel Heat

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Blonde Healey Girl

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1960 BT-7 with lots of heat entering the cockpit from the vertical Transmission cover. Engine heat comes in while driving and gets the bottom of the heater box really hot. The PO had folded a piece of carpet and stuck it between the firewall and the cover. The speedo cable comes through there also.Maybe a 1/2' gap all the way across the top. Anyone know the best way to seal this off? Thanks
 
Probably the easiest way is to apply some self stick weather stripping in the joint.

Really the panel should screw down tightly with only a narrow slot formed into the edge for the cables. I would investigate why the panel is not a snug fit.

If you want something super simple get some "3M Strip-Calk" at an auto body supply shop & jam it in the slot.
D
 
Hello Blond Healey Girl, The forward edge of the tunnel can be sealed to the firewall using a good quality rubberised sealing tape,you know the stuff used to keep drafts out of the house and is used around doors and windows. Similar treatment can be applied to the tunnel flanges that interface with the floor panels. I belive it was intended that a grommet close off the hole used to route the speedo cable through the tunnel.Additionally ,there is available bulk thermal insulation, fluffy aluminum surfaced material, that can be installed inside the tunnel and under the carpet on the cockpit side. These methods tend to cut the heat down a bit. also look at the firewall and seal off any light holes you see with clear silicone .Some suppliers may have the basic seal kits for the tunnel I am not sure I hope this helps you out. Regards---Keoke /ubbthreads/images/graemlins/driving.gif
 
BHG,
I also have a 1960BT7 and have a similar issue. Have you found out if there is supposed to be a round hole in the front cover for the cable to route through? If so where? /ubbthreads/images/graemlins/confused.gif
 
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BHG,
Have you found out if there is supposed to be a round hole in the front cover for the cable to route through? If so where?

[/ QUOTE ]

I don't think there is one. It would make it very difficult to take off/put on the trans tunnel for routine maintenance. On the BJ7 (and I'm guessing on yours too), there is just a gap in the insulation near the top of the tunnel for the cable to pass through.

Cheers,
John
 
Hi John, I was guessing that a hole had been provided in the tunnel like the BJ8's have it is a very convient way to route the cable.You do not have to remove the tunnel to access it. Similarly, removing the tunnel for routine maint is not compromised either. I think if the BT's do not have a cable routing hole I would, for simplicity, put one in and use the BJ8 Grommet for closure .-FWIW---Keoke
 
[ QUOTE ]
I was guessing that a hole had been provided in the tunnel like the BJ8's have it

[/ QUOTE ]

Hmmmm. I checked the BJ7/BJ8 body service parts list and it shows just one part number for the Gearbox cover for both models. (it also shows just one continuous front seal for the cover). The sheet metal bulkhead which makes the trans opening has a return that follows the opening but is cut out at the top (12 o'clock). This is the area for the speedo cable to go. Perhaps someone added a hole in your trans tunnel? If it is an enclosed hole (not a mouse hole), how do you remove the trans cover without first removing the cable from the back of the speedo?

o.k. I just checked the Moss catalog and they show a speedometer cable Boot (which is NA). But it doesn't show a hole in the cover ... the illustration points to the front edge of the cover. So where exactly is this hole?


Cheers,
John
 
No John ,All BJ8 fiberglass tunnels have access holes for routing the cable through. The sealing grommet is called"Boot Speeodometer Cable" It is listed as NA in my Moss Wholesale Catalog on page 143 Item #33. It is available from other sources though.Evidently the parts manuals did not note the tunnel material change mine does not show it either.Regards---Keoke----P.S. Removing the cable from the speedo is simple even in a BJ8. /ubbthreads/images/graemlins/smile.gif
 
Hi Keoke,

I was editing my post, got delayed with a phone call and see that you added the same info about the cable boot. Still curious where the hole is. Is it near the front edge?

Cheers,
John
 
Yes John, the hole is located almost on the center line of the tunnel about 3-to-5 inches back from the front edge. the hole allows the knurled nut on the speedo cable to easily pass through it when the grommet is released. -Keoke
 
I don't know for sure that the BT7 in question is the same as my BN2, but it may be.
The upper (horizontal) edge of the cover has a flange that fits against the firewall. This flange fits tightly against, & is secured to the firewall by a row of sheetmetal screws. The vertical edges of this cover are, by design, covered & sealed by the panel covering carpet being wrapped around the edges of the joint.

On the LH edge of this flange at the top, a relief is dimpled into the flange to allow pass through of the speedo & tach cables. This relief is just the width & depth of the two side by side cables & is sealed by a small amount of rope caulk.
D
 
I refolded the carpet that the PO had used and slide it back across the top and around the speedo cable. The repositioned carpet stopped about 85% of the airflow. Of course this required at least a hour drive through the mountains this afternoon to figure out the temp difference!!! The vertical piece seems different from the tunnel? I'll get down there with a light and investigate as Dave suggested. Thanks for all the input, will post findings!!!
 
I've sealed my transmission tunnel / floor joint with low modulus silicone caulking - it's weak enough to break away if I need to remove the tunnel, but has stopped entirely the 'heat leaks' from hot air passing under the car from the engine bay.

(Same stuff is quite good at retaining the beading that incorporates the door seals)
 
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... still have heat flow from around the hand break. Does anyone else have this problem?

[/ QUOTE ]

Yes, I had this and the heat just blasts right onto the passenger. I used some flexible non-hardening chaulk rope to seal from the inside of the drive shaft tunnel. Hard to get to but it really helped. There might be a seal or gasket needed for this area. I will be investigating this when I put the BJ7 back together .. will let you know if I find a better solution.

Cheers,
John
 
/ubbthreads/images/graemlins/savewave.gif
No John/ TH, I do not have heat flow from around the Hand Brake Assy. Did you happen to notice that the cut out around the hand brake is stikingly familiar with another cut out in the transmission tunnel?? Well it just happens that it is the same as the tranny dip stick plug hole. SO?-So take one of these plugs grind the center handle part flush with the rest of the plug body.Mark and cut the two mounting holes pus one for the Pivot keep holes tight fitting. Remove brake, install plug,seal leather cloth back over plug and reinstall brake Assy. No more heat hole.---Keoke- /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/patriot.gif
 
On my BN2 I glued a piece of vinyl cloth to the tunnel over the large cutout. The material fits between the ratchet mechanism & the interior side of the tunnel. Only a small hole is needed for the inner end of the shaft to fit through & two small holes to fit over the spacers. The holes are a tight fit over their respective parts. Stops the hot air & is easy to do.
D
 
I also have a BT7. It was incredibly hot - it was like driving a wood stove! I had the same problem with heat coming in thru the top of the tranny tunnel. I put a strip of foam in the spaces and that seemed to cure it. I also used something like a foam blanket over the tranny cover, floor boards etc. Then material is similat to those foam coolers you put your beer can in. I got it from JC Whitney. I also have that batting with the foil on it. Makes it all a little to thick but it has worked out OK. I was lucky enough to blow up the engine a couple of years ago so I was able to add those heat shield panals while the engine was out. Its still to hot, but I gues that's part of the charm
Bill
PS - there are no holes for ther speedo cable in my tranny tunnel
 
HI Dave, The BJ8 cars came that way .However, it seems that the heat and oil mist would cause the adhesive to fail and heat would still come in.The technique I used stops oil mist from staining the carpet and solves the heat problem too,-FWIW---Keoke
 
/ubbthreads/images/graemlins/savewave.gif

Bill, be patient we will find a source for the grommet and then you can add a hole in the tunnel for routing the speedo cable through.Actually it is quite handy-Keoke /ubbthreads/images/graemlins/smile.gif
 
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