After dropping off the drive shaft and A13.1 gearbox, changing the flywheel and the clutch to Lublin-type, now the chassis must be modified to accommodate the longer TS5-21 gearbox: the handbrake must be moved around and new supports must be added.
Le Żuk/grzmiący rydwan describes this procedure (in polish) but goes the extra mile since he wants to change the engine height, requiring him to cut pieces of the chassis to give room to the drive shaft, while I want to have my drive shaft with the exact same angle and height as originally, so there is no reason at all to alter the chassis in this regard, the only difference should be the engine difference of length. And he also goes for a custom bushing for the support, while I’d like to use the original A13.1 one which have similar attachment dimensions as the original TS5-21 for Lublin – but that will require further checks, in situ, to make sure it fits exactly in height.
What is the deal with the handbrake support you might wonder? The TS5-21 speedometer location is exactly just where the blue part below is. According to Le Żuk/grzmiący rydwan, it is enough to move slightly lower the red part, it wont prevent the handbrake to function and it won’t prevent the speedometer cable to be mounted anymore.
Using a conservative approach, I decided not to move the red part but to actually make similar one:
This new part as been aligned and installed just under the original red one:
If the difference between A13.1 and TS5-21 is only about 105mm, the support location of A13.1 is next to the clutch while TS5-21 is at the exact opposite, next to the drive shaft.
This require planning, so I made some old-school rough cardboard templates. The support bolts are drawn as
|:| (A13.1) and
:| (TS5-21) and you can see how their location differs, the TS5-21 support bolts being outside of the actual space occupied by A13.1, so much further away from the engine.
This cardboard template is also practical to get an idea of where the shift lever will popup, and it looks like it’ll even more straight-forward than it was:
Next here are the home-made two pieces needed to mount the supports. No t pretty but should be sturdy enough:
I made the holes before welding the parts on the chassis, since it is convenient to do on the work bench. But it proved to be a dumb idea, because, afterward, I had to enlarge some holes in length, due to slight difference in position of parts, once adjusted and weld. It is actually way easier to adjust the pieces without caring much for holes location and to drill them exactly where they need to be afterwards.
As visible there, it is not only enough to put the new support further back on the chassis, it is also necessary the cut a small piece of the triangular chassis support in the angle.
I did not made pictures of the welding process because it is already quite unpractical to weld under the vehicle, paying attention to everything, so I was not in the mood to remove the two layers of gloves at each step. But the approach is always the same: place the part tight with magnets, weld a few points so it held in proper place, remove the magnets and check if it properly placed, if satisfying, then weld lines.
As said, I had to redrill some holes, because obviously every bolt as to go in place smoothly, and 0,3 mm difference matters here. Seems fine for now but it’ll require special attention when mounting back the engine and the transmission shaft.
To be continued! PS: the gearbox support will need to be altered also, but that will be done only when the new gearbox is in place, since we do not have precise data to predict how exactly it needs to be done.
- (summary: why and how)
- drop the drive shaft and the A13.1 gearbox;
- replace the flywheel to Lublin-type and install a new clutch;
- adjust chassis elements that would not adapt to the TS5-21 gearbox dimensions: gearbox support, handbrake support;
- prepare TS5-21 gearbox and the drive shaft;
- mount the TS5-21 gearbox along with the revised drive shaft;
- finally setting up the gearbox support within parameters.