Bristol Cars - Owners and Enthusiasts Forum  

Go Back   Bristol Cars - Owners and Enthusiasts Forum > Bristol Forums > 8 & 10 cyl Bristol cars

8 & 10 cyl Bristol cars Type 407 onwards - restoration, repair, maintenance etc

408 front subframe / crossmember removal

Reply
 
Thread Tools Search this Thread Display Modes
  #21 (permalink)  
Old 29-01-23, 10:52 PM
Member
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 1,170
Default

Quote:
Originally Posted by Thomas591 View Post
This is for my 411 S5, I do not know if earlier cars used BSF screws instead.
Thomas,
I'm pretty sure on my 411 S5 they were all still BSF.
Regards,
Kevin
Reply With Quote
  #22 (permalink)  
Old 29-01-23, 11:10 PM
Member
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 1,170
Default

David,
I thought this may be useful/interesting - it's a strength test comparison between BSF and UNF
https://reports.aerade.cranfield.ac....=1&isAllowed=y


Kevin
Reply With Quote
  #23 (permalink)  
Old 29-01-23, 11:20 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Thanks, Kevin. I think the UNF will be fine in most locations.

You may be interested to see my progress dismantling. I have done a bit each day for several days. Tomorrow, I hope to get the tubular cage out from the front of the car and the lower wishbones off. The upper wishbones are being a pain and may have to be removed after the crossmember comes out to get better access. I think I'll leave the oil cooler attached but hang it from the metal work

David
Attached Images
File Type: jpg 6. Day 4 end of day state (Copy).jpg (88.2 KB, 25 views)
File Type: jpg 20230129_143010 (Copy).jpg (120.0 KB, 26 views)
Reply With Quote
  #24 (permalink)  
Old 30-01-23, 05:02 PM
Member
 
Join Date: Mar 2021
Location: Norderstedt Germany
Posts: 106
Default

On my car definetly not. On the front subframe there was not a single BSF bolt. I collected all the original screws and measured them, then bought new ones. all UNF. Very strange...

I found a few BSf bolts on the rear axle and its suspension. But even the studs for the swingarm housings were UNF.

Quote:
Originally Posted by Kevin H View Post
Thomas,
I'm pretty sure on my 411 S5 they were all still BSF.
Regards,
Kevin
Reply With Quote
  #25 (permalink)  
Old 30-01-23, 11:09 PM
Member
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 1,170
Default

Quote:
Originally Posted by dwomby View Post
You may be interested to see my progress dismantling.
Definitely!

Quote:
The upper wishbones are being a pain and may have to be removed after the crossmember comes out to get better access.
The bolts which go through the bushes in the wishbones are probably seized with rust. They were on my 411. It's very hard to tell until you go to remove them!

Thankfully on the 411 the fulcrum bracket arrangment and the way the wishbones are fixed to the crossmember is a little different, which makes it easier to get them out.

Good luck and please keep the photos coming!
Kevin
Reply With Quote
  #26 (permalink)  
Old 30-01-23, 11:39 PM
Member
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 1,170
Default

Quote:
Originally Posted by Thomas591 View Post
On my car definetly not. On the front subframe there was not a single BSF bolt. I collected all the original screws and measured them, then bought new ones. all UNF. Very strange...

I found a few BSf bolts on the rear axle and its suspension. But even the studs for the swingarm housings were UNF.
Well now you have got me wondering Thomas Maybe I am making assumptions! It was 20 years ago and I must admit I didn't measure every nut or bolt, and some of the work was done by a third party. I'll have to go back and look at what he supplied and what I bought from Bristol. I know for sure that the "thin turret nuts" that secure the upper wishbones to the crossmember were bought from Bristol and they were 1/2" BSF.

I was given the impression by Bristol at the time that many suspension parts carried through from the 407, 408 & 409 to the 410 and 411 (and probably the 412). Certainly many of the parts I bought from Bristol for my 411 had 407-409 part numbers.

Is it possible your car had already had restoration work done and someone had already replaced most the BSF nuts and bolts with UNF?

Regards,
Kevin
Reply With Quote
  #27 (permalink)  
Old 03-02-23, 07:51 AM
Member
 
Join Date: Mar 2021
Location: Norderstedt Germany
Posts: 106
Default

Darn! You got me… I was a bit over-enthusiastic in my statement „not a single BSF“. Yes the thin turret nuts are definitely BSF. I had these nuts glass-blasted and zink plated, so these were not on my list. Sorry for that..

Regards

Thomas


Quote:
Originally Posted by Kevin H View Post
Well now you have got me wondering Thomas Maybe I am making assumptions! It was 20 years ago and I must admit I didn't measure every nut or bolt, and some of the work was done by a third party. I'll have to go back and look at what he supplied and what I bought from Bristol. I know for sure that the "thin turret nuts" that secure the upper wishbones to the crossmember were bought from Bristol and they were 1/2" BSF.

I was given the impression by Bristol at the time that many suspension parts carried through from the 407, 408 & 409 to the 410 and 411 (and probably the 412). Certainly many of the parts I bought from Bristol for my 411 had 407-409 part numbers.

Is it possible your car had already had restoration work done and someone had already replaced most the BSF nuts and bolts with UNF?

Regards,
Kevin
Reply With Quote
  #28 (permalink)  
Old 03-02-23, 07:53 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Just to let you know I am stalled for a bit trying to work out how to remove the overtightened, hard to access and oddly shallow bolts holding the crossmember to the front of the main chassis rails. We have guests for a few days too so I won't be touching the car until next week.

David
Reply With Quote
  #29 (permalink)  
Old 13-02-23, 09:25 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Progress. After many days of soaking the offending bolts with PB Blaster (penetrant), the 18 bolts holding the crossmember to the front of the frame rails have all been loosened ready for removal. The steering U-Joint has been disconnected from the steering box and the tubular frame ahead of the crossmember is all loosened up too.

One challenge remains before I try to actually remove the crossmember: there are bolts holding the inner fender wall to the top of the crossmember and, so far, I haven't got any of them out. There are 4 each side on the 408 (I think later cars only had 3) and they are partially hidden by a large ridge on the top of the crossbeam. It makes getting a socket on there impossible. So I will have to put a wrench there and use the socket inside except the clearances by the manifolds don't leave room for a socket there either on the rear two bolts each side! I attempted to cut the head off one bolt but I was trying to be sure I didn't cut the metal the bolt passes through and didn't cut far enough in so I cut the head, not the threaded neck!!!!

I think I'll be able to do it with help and a neighbour has offered to assist later this week.

David
Attached Images
File Type: jpg 20230213_145854 (Copy).jpg (133.4 KB, 19 views)
File Type: jpg 20230213_145916 (Copy).jpg (120.2 KB, 20 views)
Reply With Quote
  #30 (permalink)  
Old 14-02-23, 06:05 AM
Member
 
Join Date: Mar 2021
Location: Norderstedt Germany
Posts: 106
Smile

Hi David,

I used an angle grinder with a thin disc to grind off the heads. Don’t worry about the sheet metal of the inner fenders a lot, when you have the front crossmember out you will anyway clean and repaint them ..
Regards

Thomas
Reply With Quote
  #31 (permalink)  
Old 14-02-23, 04:16 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Quote:
Originally Posted by Thomas591 View Post
Hi David,

I used an angle grinder with a thin disc to grind off the heads. Don’t worry about the sheet metal of the inner fenders a lot, when you have the front crossmember out you will anyway clean and repaint them ..
Regards

Thomas
Yes, I may well end up doing similar.

David
Reply With Quote
  #32 (permalink)  
Old 19-02-23, 10:04 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

In the end, I did grind off those bolts holding the fender wall to the crossbeam.

The front crossbeam is now completely detached from the chassis and body of the car but is still not removed.

The pic below shows the problem: I can't get the u-joint off the splined end of the steering column. It has to come out as the u-joint is inside the crossbeam and the hole the steering column passes through is too small for the U-joint to go through to take it out of there. I have removed the clamping bolts on both ends of the u-joint and the steering box end slides freely. The steering column end will not shift. Applying leverage just pulls the whole steering column down towards the steering box by about 1/2". I have applied PB Blaster penetrant, I have applied heat (albeit with only a small propane torch) and I have hammered a chisel in there (many, many times) but it won't separate from the column splines.

Any suggestions, please? I am considering just cutting the column to get it out but will have to check what would be entailed in repairing it and what parts may be needed and available.

David
Attached Images
File Type: jpg 20230219_163458 (Copy).jpg (127.9 KB, 16 views)
Reply With Quote
  #33 (permalink)  
Old 20-02-23, 07:23 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Success!!!!!

I applied the propane torch for 30 minutes today. Then after some levering with a pickle fork, the spines came clear of the u-joint. Thanks for all the advice that got me to this point.

Here's the suspension subframe/crossbeam out of the car!!!!! Once I have dismantled the steering and upper wishbones, it will go to the welder for repair of the rusted out areas.

David
Attached Images
File Type: jpg 20230220_131308 (Copy).jpg (98.6 KB, 15 views)

Last edited by dwomby; 21-02-23 at 11:50 AM.
Reply With Quote
  #34 (permalink)  
Old 21-02-23, 04:35 AM
Member
 
Join Date: May 2008
Location: Melbourne, Australia
Posts: 1,170
Default

Well done David!
That was quite a job! Must be very satisfying to get the subframe off. In some ways it's fortunate that you are restoring everything because it means get the angle grinder out if need be.

Looking forward to seeing how you tackle the Wishbone Challenge :-)

When you get the wishbones off, in the past I wrote a post about getting to bushes out.

Probably don't need to tell you this, but make sure you clearly mark the wishbones arms so they can be re-assembled exactly where they were orignally.

Kevin

Last edited by Kevin H; 21-02-23 at 02:11 PM.
Reply With Quote
  #35 (permalink)  
Old 21-02-23, 07:35 PM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

Thanks, Kevin. It's going to be a long process getting this repaired and reassembled....................................... ............

David
Reply With Quote
  #36 (permalink)  
Old 02-05-23, 09:21 AM
Member
 
Join Date: Oct 2014
Location: Florida / Nova Scotia
Posts: 261
Default

The subframe is back from the welder!!!!

The first pic shows the worst of the rusted area after the frame had been in an acid bath. The second shows the same area. The control arms are just being test-fitted.

The plan is eventually to paint this black but I am leaving for Nova Scotia very soon and won't be back until September. So, for now, I will temporarily bolt the subframe back in 'as is' to ensure the main chassis rails don't spread apart under the weight of the engine during the summer. The engine has been supported while the subframe has been out. So it should bolt straight back in but we'll see how it goes!!!!!

David
Attached Images
File Type: jpg acid2.jpg (62.4 KB, 23 views)
File Type: jpg Back from welder 2.jpg (68.7 KB, 24 views)
File Type: jpg Back from welder 1.jpg (85.0 KB, 21 views)

Last edited by dwomby; 02-05-23 at 09:34 AM.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


All times are GMT. The time now is 05:14 AM.


This is the live site

Content Relevant URLs by vBSEO 3.6.0 PL2