Grantura mk IV 1800s restoration

Grantura mk IV 1800s restoration

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Discussion

tvrsloth

Original Poster:

72 posts

112 months

Saturday 5th September 2015
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Starting restoration of my Grantura, have removed body and assessing chassis.

Rear differential is modified to take a Jag diff and is mounted on this bracket from the top only, the 3 points are bushed but I think it should be secured from the lower side as well, what do you think?



Also noted that the input drive for diff is offset to the right due to the design of the diff, i know the universal joints will allow for offset but should this be mounted to be as central as possible ink both planes.



I am missing few parts need to bonnet release mechanisms, fuel tank and rear lights so far.

Everilda

48 posts

117 months

Saturday 5th September 2015
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Have a look here to see how a grantura diff is mounted http://www.nigelreubenracing.com/gallery.php towards the bottom
of the pictures.

It is totally different to the Jag diff. You are correct in thinking the Jag diff should be supported underneath.
it should be mounted in a steel cradle bolted to the diff two bolts either side, with a rubber bush mounting to the chassis
just underneath the diff nose.

The diff offset is OK, if you move the diff over the drive shafts will be uneven lengths.
The chassis looks as though is has been modified to take a V8 because the engine mounts are not for a MGB engine.

Some more detailed pictures would be nice.
Good luck with your project.

K

GTRene

17,790 posts

231 months

Saturday 5th September 2015
quotequote all
I would like a diff with as much as possible centred input drive for diff.
I believe some 5000M used a Corvette diff I believe, also strong I guess, don't know what type though.

No idea what would fit best in those older TVR's with a centred input drive.

tvrsloth

Original Poster:

72 posts

112 months

Saturday 5th September 2015
quotequote all
They had an option of a Jag or corvette diff fitted to the griffs when they were modified from grantura's so this should fit as it is a period diff.

The chassis here is a Griffith chassis I believe, I have the original chassis and rear diff but not sure whether to repair or use this one.

I need to look at a few other cars see what I am missing so if anyone has a griffith or grantura/vixen around the Midlands and happy for me to take few pics I would be grateful.


[quote=Everilda]Have a look here to see how a grantura diff is mounted http://www.nigelreubenracing.com/gallery.php towards the bottom
of the pictures./quote]

I like the modified race diffs Nigel has produced not sure how much they are but that might be an option.

Sonus

294 posts

190 months

Sunday 6th September 2015
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My jag diff is mounted offset Just like yours. Works fine as long as the angles are parallell. Mine has the lower diff cradle as mentioned earlier. Plenty pictures in my photobucket account.

Edited by Sonus on Sunday 6th September 17:08

tvrsloth

Original Poster:

72 posts

112 months

Sunday 6th September 2015
quotequote all


Hi Should my car have the recess for the lucas style number plate/reverse light or would it have had the smaller mgb style which has no reverse light on it?

thx Neil

status

251 posts

224 months

Sunday 6th September 2015
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For comparison, Salisbury diff mounting on Taimar...

Top mount


Bottom mounts to rear of chassis


cheers
Nick

tvrsloth

Original Poster:

72 posts

112 months

Monday 7th September 2015
quotequote all
SONUS

Do you have link to your photobucket account images please, I would be interested to see how yours is mounted.

thx Neil

Sonus

294 posts

190 months

tvrsloth

Original Poster:

72 posts

112 months

Monday 7th September 2015
quotequote all
Sonus said:
thx nice pics, yes see yours is offset the same, but i prefer your mount set up i am going to design new one for mine once I have new gearbox to check position.

Sonus

294 posts

190 months

Monday 7th September 2015
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I believe mine is the same as the tuscans (?)

tvrsloth

Original Poster:

72 posts

112 months

Tuesday 8th September 2015
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Hi Neil

Thanks for pictures, I like the set up you have think I will look at modifying my chassis the same way to take diff, are you selling kits lol.

I was told that this was a griff 200 chassis but to be truthful I am not 100% sure on the differences, I have the removable lower centre bar below the high bell housing tube and the engine mounts look different to grantura mounts.
I will add more pictures when home.

thx Neil

chassyman

103 posts

165 months

Tuesday 8th September 2015
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just some info for those who are bothered,there is a difference in the rear lower central rails of a griff and a grantura, the griff being wider to accommodate the salisbury diff with it's lower support bracketry. the two cars use the same lower wishbones, the mounting lugs of the griff being shorter to offset the lower tubes being wider. do you follow? best regards keith

tvrsloth

Original Poster:

72 posts

112 months

Tuesday 8th September 2015
quotequote all
Please correct me if I am wrong but there are 2 types of griffith chassis?

The first being the chassis for the 200 then the second being the chassis for the 400 which has a modified rear end to take the uprated suspension components.

So could this be an griffith 200 chassis with original specification rear?

Are there other design/mods that identify them?

It does have a hammered narrow tube between the right hand upper and lower main inner chassis rails, around the area the bell housing would be.




Your ideas please.


Neil would love to make race car out of it as i used to race bikes and miss the fun, would love to chat with you and see all that is needed, away from my wife so she does not know how much I will spend.

thx Neil

Edited by tvrsloth on Tuesday 8th September 16:29

chassyman

103 posts

165 months

Tuesday 8th September 2015
quotequote all
hi, yes you are quite right, the 200 series having the weedy tvr diff in it and small drive shafts. it was mounted by use of two longitudal bolts, north to south that is, passing through two lugs cast into the diff casing on the underside to meet and pass through a depressed tube, (bow) with two sleeved holes in it to accept the bolts. further stability was obtained by a bracket off the diff flange facing forward to pick up on a sort of 'U' bracket welded on the bottom tubes. i can see that the original upper diagonals have been cut off. now on the 400 these diagonals are located in front of the upper wishbone mounts leaving room for a fabricated shallow box with a sleeved hole in it welded to the upper rear rail to accept the bat wing assembly as shown in the other photo. on the 200 they have two tabs on them to pick up the top stabilizing bolt bracketry.it all sounds a bit much i know but if they were side by side all would be so clear. looking at the space between your lower suspension arm bush and the chassis there is a gap and on a 400 it is minimal. hope you understood all that guff because if you did explain it to me!!!!!!!!!!! best regards keith

chassyman

103 posts

165 months

Wednesday 9th September 2015
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one picture is worth a thousand words. best regards keith

tvrsloth

Original Poster:

72 posts

112 months

Sunday 13th September 2015
quotequote all
Does anyone know the metal specification for the grantura/vixen chassis please?
I am after new tube material and flat sheet.

Dollyman did you have the bushes made specially for that rear differential mount?

Thx Neil

tvrsloth

Original Poster:

72 posts

112 months

Sunday 13th September 2015
quotequote all
I am going to build it for road use, but also track days etc.

Not going full racing as i can not afford to do it to the level my competitive nature would want me to.


anonymous-user

61 months

Sunday 13th September 2015
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Another option?



I know it's M series, but same principle or?

tvrsloth

Original Poster:

72 posts

112 months

Friday 18th September 2015
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Well with only 4 hits of a hammer and 8 on the other both the modified rear diff mounts fell off.