Tasmin Door Hinge Bush
Discussion
Has anyone replaced the lower bush on their door hinge? Looking at the job it looks like a fairly simple job. (i) undo the lower hinge spindle nut (ii) undo the two bolts holding the hinge to the body (iii) drop off hinge plate assembly and old bush & spacer (remembering to support the door! 
) (iv) fit new bush (V) reassemble. Is it really that simple? Oh and mustn't forget (vi) swear loudly when it's all back together and it's made absolutely no bloody difference 
) (iv) fit new bush (V) reassemble. Is it really that simple? Oh and mustn't forget (vi) swear loudly when it's all back together and it's made absolutely no bloody difference 
adam quantrill said:
I guess most of the weight and wear is on the lower one though isn't it?
Errr... surely if the door's 'pushing' on the bottom bush then it's 'pulling' on the top one an equal amount? Also if the door drops then the hinge pin leans which must exacerbate wear on the top one...?It's not as if a wheel bearing wears out just one race
v8s4me said:
....If it aint broke, don't fix it 
Well it didn't quite work out that way.....
One of the lower threaded inserts had broken out and had to be glassed back in ....
This was a right bug
er of a job! It was the threaded inserts which caused most of the problems. If I was doing this again I'd drill out the threaded holes so the bolts were a close sliding fit. This would have made life a lot easier. The sag has gone but let's just say it has been a bloody long day!adam quantrill said:
@Ian - maybe, but there's the "gravity of the situation"...
yeah I just generally grease mine to pump them up, but beware the hinge can take a big bucket of grease before it's full.
You beat me to it, I was going to say that the hinge tube takes a lot of grease to fill it before any pressure is generated to force it through the bushes... and there's another issue: Nylon-66 reacts with petroleum-based grease and swells, so what's the betting that over-greasing actually accelerates wear on the bushes as they're constantly 'nipping up' on the pivot pin.yeah I just generally grease mine to pump them up, but beware the hinge can take a big bucket of grease before it's full.
Nylon-lined throttle cables on motorcycles are expressly NOT to be oiled or greased for this reason: the Nylon liner swells and jams the throttle cable!
Only an inert grease like silicon should be used on Nylon, as far as I'm aware (and I don't think it doesn't come in 400g cartridges for grease guns). A better way of doing it would be to drill and tap the hinge tube & bush at each end for an oil nipple and use silicon oil.
Wedg1e said:
....... and there's another issue: Nylon-66 reacts with petroleum-based grease and swells, so what's the betting that over-greasing actually accelerates wear on the bushes as they're constantly 'nipping up' on the pivot pin......
The pivot pin was sized solid in the old bushes - so thats the explanation then. The pin had to be hammered out with a drift and a larger drift and a hacksaw blade to remove what was left of the old bushes from the hinge tube. The ID of the new bushes is 1mm more than the dia of the pin, which seemed odd, and has meant I've had to pinch up the nuts on the ends of the pin more than I'd prefer.I didn't know about the reaction issue (assuming the new bushes are made of the same stuff) so I packed the tube with LM grease. I'm bug
ed if I'm taking it all apart again though. Someone else can do that in another 35 years or so 
I must admit I'm a bit taken aback, I thought even the early Tasmins had the internal A-post steel reinforcements to which the hinges were bolted, rather than to inserts in the bodyshell.
Certainly the steering column on the early cars was floppier than Rolf's sausage, being hung off a foot-long tripod that was bolted through the GRP above the brake servo. Later cars got a transverse brace between the A-pillars (maybe that's when the A-post tubes were added) and the column got a bit more rigid. They also got a cross-brace between the B-posts... which unfortunately passed right through the line of the seatbelts FFS
I've never understood why they didn't reposition the seatbelt reels above the cross-brace.
TVRs, don't you love 'em
Certainly the steering column on the early cars was floppier than Rolf's sausage, being hung off a foot-long tripod that was bolted through the GRP above the brake servo. Later cars got a transverse brace between the A-pillars (maybe that's when the A-post tubes were added) and the column got a bit more rigid. They also got a cross-brace between the B-posts... which unfortunately passed right through the line of the seatbelts FFS
I've never understood why they didn't reposition the seatbelt reels above the cross-brace.TVRs, don't you love 'em
Wedg1e said:
......I thought even the early Tasmins had the internal A-post steel reinforcements to which the hinges were bolted, .....
I've got those as well! Hinge bolts screwed into the "bobbins", bolts extend through these, then through a hole in in a steel plate which is welded to the 'A' post brace and then bolted up again with a nylock. What a "design"! It took two of us nearly 1 1/2 hours to refit the door because the most you can get on each hinge bolt is about a 1/32nd of a turn at a time with a ratchet ring-spanner. The forward bolts have to be done up first because you can't get the spanner on them when the rear ones are in place. Because of the access, the door has to be held off so the the front bolts can be rotated gently by fingers to make sure they thread cleanly into the "bobbins" and don't get cross threaded.....I thought even the early Tasmins had the internal A-post steel reinforcements to which the hinges were bolted, .....If this is how the doors were assembled in the factory then 1 man-hour per door is ridiculous (assuming the blokes there were quicker than us and had a better selection of bent spanners) . "Design"? Yer 'avin a larf mate.
v8s4me said:
I've got those as well! Hinge bolts screwed into the "bobbins", bolts extend through these, then through a hole in in a steel plate which is welded to the 'A' post brace and then bolted up again with a nylock. What a "design"! It took two of us nearly 1 1/2 hours to refit the door because the most you can get on each hinge bolt is about a 1/32nd of a turn at a time with a ratchet ring-spanner. The forward bolts have to be done up first because you can't get the spanner on them when the rear ones are in place. Because of the access, the door has to be held off so the the front bolts can be rotated gently by fingers to make sure they thread cleanly into the "bobbins" and don't get cross threaded.
If this is how the doors were assembled in the factory then 1 man-hour per door is ridiculous (assuming the blokes there were quicker than us and had a better selection of bent spanners) . "Design"? Yer 'avin a larf mate.
I wonder if the shell has probably moved around on its packing rubbers and that's what fractured the bobbin out.If this is how the doors were assembled in the factory then 1 man-hour per door is ridiculous (assuming the blokes there were quicker than us and had a better selection of bent spanners) . "Design"? Yer 'avin a larf mate.
I do recall reading that there were a couple of factory special spanners to fit the doors but that could have been doors to hinge tubes.
The other problem is that the steel hinge tube into which the bushes press wont be straight...... Where it is welded onto the door chassis (DHC im assuming) the flipping great welds distort the bush tube, so nice new, tight-fitting bushes may well not work too well because the inner diameters wont be collinear or even parallel with each other, and therefore not with the pivot pin.
Nice one TVR...! the best bet might be to fit the bushes with undersize IDs and then line ream them. The pin will probably also be worn.
I have machined parts like this is in the past, but unless you're prepared to do some re-engineering, getting nicely hinged doors with no slop isn't a simple fix.........
Nice one TVR...! the best bet might be to fit the bushes with undersize IDs and then line ream them. The pin will probably also be worn.
I have machined parts like this is in the past, but unless you're prepared to do some re-engineering, getting nicely hinged doors with no slop isn't a simple fix.........
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