Jump to content

300tdi and r380 alignment in TDI 90 chassis?


Recommended Posts

I'm in the middle of rebuilding the above parts into a secondhand TDI chassis. The way the whole thing sits in the chassis looks a little wrong to me so tell me what you think. ......The handbrake drum is around 3 inches away from the offside chassis rail, and the timing cover ends up really close to the steering box. To my eye if the transmission mounts were moved over towards the offside by about 1.5 inches it would be better. See photos

1. I reused the chassis cross member from the old chassis and did not use the 300TDI cross member - mainly because previous owner had modified the cross member to clear the exhaust..... And I suspected the 300 TDI cross member would foul the exhaust. Current mounts are I believe lt77.

2. Propshafts fit okay. And engine fitted right in on the unmodified TDI chassis engine mounts

3. Previously the engine ran with its viscous fan, whereas now it will need electric fan, and I presume that the old chassis had NA engine mounts and were modified -although it went into the bin years ago so I can't really verify

4. I realise a short bell housing r380 would be a lot better but unfortunately I'm stuck with what I've got :)

Thoughts please... 20240309_145447.thumb.jpg.1be8f4d523caf6949f0137f120ea410e.jpg

20240309_145957.jpg

20240309_150222.jpg

20240309_150336.jpg

Edited by joe1
Add 90 to chassis spec
Link to comment
Share on other sites

  • joe1 changed the title to 300tdi and r380 alignment in TDI 90 chassis?

It may be an optical illusion but engine and box seem to be sitting slightly diagonally in the chassis, a reposition of mounts should square things up. I wouldn't be overly concerned plenty modified trucks running only adequate clearances

Regards Stephen

Link to comment
Share on other sites

53 minutes ago, Stellaghost said:

plenty modified trucks running only adequate clearances

 

LGT has literally a fingers width between PAS pump pulley and radiator outlet :ph34r:

Link to comment
Share on other sites

Something certainly looks wrong and it may as previously stated that it could be an optical illusion but the timing cover looks to be too far back compared to my 300TDI (see picture).

 

Picture_1.jpg

Link to comment
Share on other sites

On 3/9/2024 at 8:19 PM, Stellaghost said:

It may be an optical illusion but engine and box seem to be sitting slightly diagonally in the chassis, a reposition of mounts should square things up. I wouldn't be overly concerned plenty modified trucks running only adequate clearances

Regards Stephen

It looks fairly significantly twisted clockwise (from above) relative to the chassis.  I don’t think that is an illusion.

 

12 hours ago, Hawklord said:

Something certainly looks wrong and it may as previously stated that it could be an optical illusion but the timing cover looks to be too far back compared to my 300TDI (see picture).

 

 

It inferred it is a retrofit into a 200Tdi chassis, using the 200Tdi spec rear cross member.  That would put the engine in a different longitudinal position to a standard 300 vehicle.

 

Joe, I suspect most of your issues are from the cross member having different mountings to the 300 cross member.  It’d be worth comparing and perhaps transferring the mounts.  I would also double check the engine mountings on the chassis are fitted ont he correct sides, as they are probably asymmetric and that would cause this skew if fitted reversed.

Link to comment
Share on other sites

On 3/10/2024 at 4:29 PM, Hawklord said:

Something certainly looks wrong and it may as previously stated that it could be an optical illusion but the timing cover looks to be too far back compared to my 300TDI (see picture).

 

Picture_1.jpg

That looks to be the answer. I've spent some time this week swapping in a TDI gearbox cross member.... Just look how far out the transfer box Mount is in relation to the cross member....the whole engine and gearbox is sited about 4cm too far to the rear....and this is despite the fact that the chassis engine mounts appear to be  original position (I'm currently searching for some tech drawings to give original chassis dimensions). Duh!!

20240314_160625.jpg

Link to comment
Share on other sites

For 200Tdi and earlier 4-cyl models the engine/boxes sit in that rearward position, using the bolt-on mounts you have in the first post.

For the 300Tdi they moved the mountings forward a few inches, into the V8 position. This means the gearbox tunnel is a different shape at the rear to clear the front output housing of the transfer box. Combined with a longer bellhousing on the R380 it means the engine ended up much further forward in the engine bay.

A picture of your engine mounts would be useful. With the gearboxes mounted on the 300Tdi crossmember then your engine should drop on to standard 300Tdi mounts. 

Link to comment
Share on other sites

1 hour ago, Retroanaconda said:

 

A picture of your engine mounts would be useful. With the gearboxes mounted on the 300Tdi crossmember then your engine should drop on to standard 300Tdi mounts. 

It's interesting that the chassis engine mounts appear to be the OEM ones because I can't see any signs of modifications in that area. Not a very good photo below but they are horizontally flat mounts which made me think they must be 300 TDI mounts. 

However if I do relocate the engine mountings to match the 300TDI crossmember then the propshafts will probably be wrong (I'll attach photos of these prop shafts as well the total length of rear prop shaft is round 67/68 cm and front is about 70/71cm). Btw it's also looks like the original owner had trouble with fitting because the exhaust-down pipe has been cut and welded.

I've got a few more measurements I've taken on the chassis....

1) from rear edge of near side chassis engine mount to center the transmission crossmember mounting slot NS is 75.5cm

2) from rear edge of front cross member box section (ie the rad support member) to the front of the NS engine mount is 56.5cm

20240315_114855.jpg

20240314_164559.jpg

20240314_164605.jpg

Link to comment
Share on other sites

On 3/11/2024 at 5:10 AM, Snagger said:

It looks fairly significantly twisted clockwise (from above) relative to the chassis.  I don’t think that is an illusion.

 

It inferred it is a retrofit into a 200Tdi chassis, using the 200Tdi spec rear cross member.  That would put the engine in a different longitudinal position to a standard 300 vehicle.

 

Joe, I suspect most of your issues are from the cross member having different mountings to the 300 cross member.  It’d be worth comparing and perhaps transferring the mounts.  I would also double check the engine mountings on the chassis are fitted ont he correct sides, as they are probably asymmetric and that would cause this skew

Interesting. So if this is a 200 TDI chassis would that explain the differences I'm seeing.....ie engine sitting further back than in a standard 300tdi....and  not being able to line up a 300 TDi gearbox cross member with the rubber mountings

I've double checked the handedness of the lt77 transmission mounts and these are on the correct sides..the nearside bracket with a curved bottom section to clear the exhaust

I haven't as yet compared the handedness of the rubber engine mounts... These were as fitted in an original disco that was running around

Link to comment
Share on other sites

The answer is to do with the fact that the chassis engine mounts have at some point been moved rearwards by around 45mm. I found someone's diagram (attached) for installing 300 TDI mounts (in a standard 300 TDI position) together with measurements and once I knew where to focus attention I could see (minimally) the original signs of mount locations.

The 300tdi cross member made the situation worse because it tries to move everything forwards by around 4cm too.... In that case my existing prop shafts will be useless so I'm going to opt for using lt77 gearbox mounts, hang the engine and gearbox off those whilst deciding on the best place to relocate the existing engine mount brackets to....... I can also raise the mounts very slightly because currently the timing belt case is incredibly close to the pas box. Many thanks to everyone here who have been with this epic saga!

Dimensions of RH bracket.JPG

crossmember bracket start point.JPG

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy