235/5 CR Trans

[markmac]

I have used Terry Tinney on a whole host of projects, I might snap a couple of pics of it just to get his thoughts. By the time it gets taken off, shipped, at least four hours (Guessing) to fix it, magnaflux it, ship it back, going to be pretty close to the cost of new (assuming you can get 'new' from someone).  And things like this are part of the reason why its taken 20 years to build the car.

 

I am a little surprised as well that the trans builder guy installed it - going to have to have a discussion with him on that one.

[Mikesmalaga72]

Never hurts to get an expert opinion. Perhaps flange was just put in place to hold things together as there was no retaining nut lock plate installed to show final assembly. 

[markmac]

Jenky

[Mikesmalaga72]

1 hour ago, Mike Self said:

What specifically makes it unique to the C/R gearbox?  Do you have specs for both flanges? 

 

If the bolt hole spacing is the same (same guibo as the other 4 and 5 speeds) and the coarse splines are the same as those boxes prior to January '74, then could you modify the 4 speed flange to work?  

 

Another thought, to at least get you back on the road--keeping in mind not to stress things by doing burnouts:  take some steel tubing with an 8mm ID, open out the existing bolt holes, weld the tubing sections in place to make the holes round again, then magnaflux and balance.  Might be the long way round, but it beats a car that can't be driven at all...

 

mike

The C/R flange has 14 splines, the other two versions for four speeds are 10 and 27 spline. I probably would consult a very good machinist to evaluate repairs/magnafluxing, etc on that existing flange. I do see your common sense that you suggested on reserved usage.  

[Mikesmalaga72]

2 hours ago, JohnS said:

Hello Mark,

  Is this the same type of output flange as used on a regular 242 4-speed?  If so, what type of splines does it have?  If it's a course splined type (10 ZAHNE), then I might have a new one for you.  Let me know.

John

 

 

14 Zahne spline.

[edgefinder]

Heres what I would do. Inspect all the holes for looseness. If they are loose then check for misslocation. A simple fixture plate with pin that fits ID inside splines in vise in machining center to see what side of holes needs build up with tig weld. Cut in with disc halfway where rust may be hiding crack on worst hole. Weld it up, cut in other side, weld it up, weld wallowed sides of other holes. Back to the mill. Chase holes with progressively bigger endmills watching that it cleans up holes on all sides. The last cuts usually require that the hole pattern gets rotated a smidge so fresh cut all the way around with relatively no clearance to bolts being used. Cut flange face to clean up. hand grind back side where bolts go in. Back on the tranny, set dial indicator to see flange face really runs true. Put close fit pin in each hole, set indicator to check radially each hole from center out is same.

 

If its soft enough to be damaged like it is then its weld repairable. If you want to trust me with it I'll do it for you for $200. Yes i'm one of those last resort go to guys who likes to put stuff back on track after everyone else throws their hands up.

 

Luke

[Mikesmalaga72]

1 hour ago, edgefinder said:

Heres what I would do. Inspect all the holes for looseness. If they are loose then check for misslocation. A simple fixture plate with pin that fits ID inside splines in vise in machining center to see what side of holes needs build up with tig weld. Cut in with disc halfway where rust may be hiding crack on worst hole. Weld it up, cut in other side, weld it up, weld wallowed sides of other holes. Back to the mill. Chase holes with progressively bigger endmills watching that it cleans up holes on all sides. The last cuts usually require that the hole pattern gets rotated a smidge so fresh cut all the way around with relatively no clearance to bolts being used. Cut flange face to clean up. hand grind back side where bolts go in. Back on the tranny, set dial indicator to see flange face really runs true. Put close fit pin in each hole, set indicator to check radially each hole from center out is same.

 

If its soft enough to be damaged like it is then its weld repairable. If you want to trust me with it I'll do it for you for $200. Yes i'm one of those last resort go to guys who likes to put stuff back on track after everyone else throws their hands up.

 

Luke

Outstanding!! 

[uai]

I can sell a complete 235/5 to you for 2500€ + shipping if you'd need more spares.
However it will likely need some refresh too

[markmac]

1 hour ago, uai said:

I can sell a complete 235/5 to you for 2500€ + shipping if you'd need more spares.
However it will likely need some refresh too

Thanks for the offer, I'll sort this one out.  I actually have most of (minus output flange of course) another that needs refreshing.  If I was going to do 'another' it would probably be a 235/6 or 235/8, one of which was probably in there back in the day.

[TobyB]

Ok, if I was in your boat,

 

I'd take that flange off, re- center the holes as edgefinder suggests-

and then reinforce it.  The original was forged, and there's no way to 

get that material strength back through process, so get it back by

adding more material.  Make it a bit thicker.  Make the ears a bit bigger.

Use a metal that has high strength in its dead- soft condition, or that can 

be easily and safely heat- treated and tempered to be both relatively strong

and also not very notch- sensitive.

Crap, it might actually make sense to remake the ears separately, then attach them

to the splined flange.  Then you could use something strong but weldable.

 

Yup, it'sa lotta work.

 

In times past, there was a local metalworker who could do this, pretty much in any

town big enough to have industry.  Now, there's lotsa people who can resolve your IP,

not so many who can heat treat and temper...

 

t

bad tempered.

[Henryn02]

Retro Engineering has them on their UK Ebay shop. Say they are in stock. eBay Item #254785050848

Henry

Edited November 30, 2023 by Henryn02

[markmac]

What Toby said +100.  Few folks around anymore that have the skills to do it right and even fewer that are willing to do it.

 

There are 'some' serial 2002 parts on my car, most are not.  One off fabrication is expensive.  It is always time & materials since in most cases it just isn't possible to give someone an estimate.  The best most will do is take a guess and that is about it and really the most you can ask for.

 

This is my current opinion of Retro Engineering - bought one of those flanges through their ebay store, the contacted me and said they would get back to me with the shipping costs.  Never did,  I followed up once or twice more (which I shouldn't have to do).  Nothing.  Nada.  I emailed them day before yesterday AGAIN, nothing so far.  My expectation is low for them.

[markmac]

UPDATE:  

 

First, input very much appreciated from the greater group.  Luke (edgefinder) I do appreciate that offer.  I have some other stuff that needs doing that maybe you could help me with.  You have the skills I don't.  Time isn't super critical with things, although I do want to finish this thing before I am too old to drive it.  Grandpa will be 's-canning' that cr 5sp for a PDK! (not).

 

I emailed Walloth Nesch this morning and asked if they had an idea of when they would get a new stock of 235/5 output flanges.  I got a response within 30 minutes.  Two (2) weeks.  I asked them to email notify me when they were in stock.  Return email in less than five minutes, 'will do, will notify as soon as they come in.....'.  Still not a peep from Retro Engineering.  Things must be good for them.  Just remember that if you need to get something from them.  I have heard this from others.

[bello]

   Hey. Looked thru my collection of "spares" and found this: A 4-bolt Guibo Output Flange- 76mm bolt circle diameter, 10mm bolt holes. 42.5mm length from front face to outer face, 22.5mm trans shaft diameter. But! I can only see 22 splines...  I know it's a BMW Getrag item, but don't recall what car or trans it came from... LMK if any interest, comments, questions...  Best!   Ernie

[markmac]

The 235/5 is unique, 14 splines, it sounds like yours is different.  Thanks for checking, much appreciated.  While I wait for that part, I am going to finish off rebuilding the shift tower.

 

Gear shift support strut.  Guessing again this part is shorter than the 4sp version (it has to be given the platform is also shorter).  The bearing in there is junk.  Any ideas on where to get a replacement?  I did some googling around yesterday and didn't immediately find anything.  I need a 'bearings-r-us' superstore or some such.