TR2/3/3A TR3 Bonnet alignment

[mapleaf]

The bonnet on my TR3A needs adjusting and I'm not sure how to go about it. The fit along the scuttle plate is good, the problem is with the front edge where the bonnet sits about 1/4 inch below the apron and both front corners scrape against the wing beading. I can't see any obvious adjustment on the 'hood lift assembly' and even if there is I am not sure it would correct the problem of the edges scraping the wingbeading. Any ideas or tips on how to make the bonnet fit right will be of great help. TIA

 

[Geo Hahn]

There is, of course, some height adjustment at the front corners by altering the height of the rubber bumpers.

However, mine has always scraped at a couple of spots along the (side) edges and there doesn't appear to be enough width to adjust that away.

 

[Don Elliott]

Maple Leaf - There are pads made of fiber (box-car red/orange in colour) that you have to use as shims under the Dzus bases for securing the bonnet. I have seen up to 6 such fiber pads to get the right height and the right twist needed to lock down the front so it's at the right height.

George - If your hood (bonnet) is scraping along the trim that goes along the top of the wings (front fenders), may I suggest that you loosen the 7/16" across-flats bolts that hold the fenders to the inner wings (fenders) and move these fenders out a bit to get equal clearance on each side so nothing rubs.

 

[TR3driver]

However, you want the shims/stops adjusted to match, so the Dzus button more or less snaps into place when you fasten it. If it turns too easy (meaning too many shims or not enough bumper), it may come undone while driving.

 

[sp53]

There is also an old carpenter trick you might try. You can actually move the hood back some by just placing some additional gaskets under the back end of the rear hinge only. This lifts the hood up in the back only and will let it ride a little high in the saddle and will in turn give you a small amount of clearance on the sides as it move up and back in the back. I did this on a tr3 that the hood rubbed on the back and yet need a little room in the front. Be careful not to move it back too much or the vent will hit and you will have to slot those holes and move that back some also. From my vantage point, these hoods have sagged over the years and have spread out and can rub in odd places. When they came from the factory, they had a piece of felt placed between the hood skin and the rear brace. This was most likely to stop rattle and rubbing, but it also crowned the hood in the center and thus making it a little smaller from side to side.
Steve

 

[angelfj1]

When they came from the factory, they had a piece of felt placed between the hood skin and the rear brace.

Steve: This is very interesting! I have not been aware of this detail. Does anyone have a photo of the felt in situ?

Regards,

Frank

 

[mrv8q]

Well, sonofagun, after 50 years, mine is still hanging in there:

 

[sp53]

Hi Frank try taking a strong flashlight and look between the two hood hinges from the underside between the brace and the hood mian piece. There is a gap about an 1/8. I think you will find that the light will not go through. The piece of felt is about 4 to 6 inches wide and runs the length between the two hinges. The first time I pull the felt piece out, I figured the p.o had just done that to stop the rattle, but the second time it became less of a theory. Both times when I removed the piece, I was sand blasting the hood with 70 grit glass beads right along that seem. The sand and the air pushed it enough to grab the felt with some needle nose. It was actually kinda weird because the felt just keep coming out. In addition, the felt had rust on it from being trapped in that space. I sure hope somebody can help me verify this because my reputation is at stake here.
Steve

 

[sp53]

Thanks Kevin I can face the world.
Steve

 

[mallard]

The felt was great at causing rust under the brace. I removed the brace from the replacement bonnet and made all the repairs to the underside before rewelding and priming. I discovered this rust area from the the bonnet my wife ran over. I don't think the felt extended much past the hinge mounting points. Not sure if I will put any type of felt back in. I do need to fabricate the two rivets that helped hold the brace on though. I would like to see more pictures of the felt in place if anybody has them.

 

[Don Elliott]

When I was doing the restoration of my 1958 TR3A from 1987 to 1990, I pulled out that strip of black "jute". I still have it. It's about 1" wide, 1/4" to 3/8" thick and about 3.5 feet long. It looks like the underlay you might find under your carpets.

Ever since then, when I'm sitting waiting at a traffic light snd everyone around me thinks my TR looks super, that hood (bonnet) will vibrate something horible between 600 RPM and 1100 RPM. So I have to keep "blipping" the gas pedal.

For 20 years, putting in a new strip (or maybe the original one) has been on my list of things to do on my TR3A.

 

[angelfj1]

I discovered this rust area from the the bonnet my wife ran over.

Oh? Perchance is there more to this story. :lol:

 

[mallard]

We don't talk about it much.