Overheating LT77 gearbox?

[Marsu]

Drove home this afternoon in 34°C heat and found the metal gear knob on the gear selector became incredibly hot, almost too much to touch. The trans tunnel was similarly much hotter to touch through the carpet than what seems normal to me.


I've been running this LT77 for the last 18 months and never experienced this before. It doesn't appear to leak any oil and currently runs GM Synchro.

I'm wondering if it's an ominous sign or just an aberration? Another thought is that it could be the result of finally getting a reasonable state of tune from the DCOEs on the Sprint engine.

[PeterTR7V8]

Was the temp guage behaving normally?



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[Marsu]

Engine temp (read from the gauge) was slightly hotter than normal, but marginal only.

[edited for clarity]

[Hasbeen]

Buy a nice big wooden gear knob, & you won’t feel it’s hot.

Seriously, have you checked the oil level?

Hasbeen

[Beans]

Have had similar things happen to the Sprint (which also has a solid alloy gear knob), but never to the extent that it was too hot to touch.
It often heats up and cools down again during longer runs, while the engine temperature remains constant.

Never really found out what caused it, and as it happens quite randomly and as the ’box was/is in good condition,
I put it down to changing airflow (and thus cooling) underneath the car due to wind direction and driving speed.

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[Workshop Help]

Let's review. Our Hero says the air temperature is about 34 degrees C or about 100 degrees F. That means the sun was shining thus heating up the unshaded pavement to VERY HOT. Add the gearbox frictional heat, engine heat being drafted to the rear, and the always close proximity of the exhaust pipe and we have the case of a springtime cook-a-thon there in your car. May we suggest you keep a plastic bucket of ice with a wash cloth in it to cool you fevered brow as the miles roar by?

Oh, and please vacuum out the doughnut crumbs from the carpet and seats. We do like the decorative ashtray there in front of the shifter.

Mildred Hargis

[nick]

Maybe you didn't douse those butts in the ashtrys near the shifter. That could certainly bring up the temp a bit.


nick
'79 TR7

[Stag76]

If the oil pump is not working properly the gearbox can overheat. To test it, you have to remove a small plug in the rear cover and start the engine. If oil flows out of the hole all is OK. If not, you have to remove the rear cover to get to the pump. You have to support the gearbox and remove the rear crossmember/support to remove the plug, which is located just forward of the rear mounting point.

However, if the tunnel cover was also hot, it sounds more like heat build-up from the exhaust etc.

TR7 Convertible
Sprint Motor
MegaSquirt EFI