30-12-2012, 01:13 PM
A "Two Spanner" Haynes grade job.
You need basic mechanic's tools, plus an angle grinder with thin cutting disc and an electric or cordless drill with bits.
1. Remove the seat from the car - unplug the wiring first, then unscrew the four T-40 fasteners, taking note of the spacers under the seat (they vary in thickness by position). Unbolt the seat belt buckle stalk and slip it (with grommet) back into the seat riser.
2. With the seat in a safe place for grinding, release the seat base cover's edges from the metal riser base's side rails. Pull the cover back firmly to expose three stitch welds per side.
[Image: seatbaseweld2.jpg]
3. Grind carefully through the stitch welds, favouring a cut into the seat's tubular frame if there is a tight join. Complete one side, then flip the seat over to do the others. Set the old seat aside until the job is done - you may need to check its dimensions at some point.
[Image: seatbasetrimmed1.jpg]
4. Smooth the seat riser top edge with the grinder and disc, gently. Now lay a strip of inch masking tape along the length of each top edge.
5. Looking once again at the seat riser, note the 4mm wire "rails" that held the seat cover edges before. Where the wire rail turns up towards the riser top edge, at rear of the assembly, is your datum point. This turnup is clearly shown in the first photo. Mark the centreline of this wire turnup on your masking tape, both side - use a carpenter's square or similar if you have it.
6. On the original seat, the backrest pivot axle was 47mm past this datum. You may choose to set up your donor seat to preserve the same location. I decided to put the new seat 20mm further back, as its base was longer than the original and backrest slightly thicker.
7. This is the only slightly headbending part. First you measure from the backrest pivot axle (centreline) to the first mounting hole in the donor seat frame. For my seat, this was 60mm. You hold your ruler so the pivot distance (whether 47mm as original, or otherwise) reads on the datum line and the zero is at the pivot point. Now read from the zero, to that first bolt hole centreline and mark it on the tape. Do this both sides.
8. Now set out the other bolt holes, working each time from the first one set out on each side; don't "hop" from one to the next if there are more than two holes per side. In my case, I used all eight (four per side) as Citroën did on the Xantia donor. My spacings are quite common to various Pug/Cit cars and were (between centres) 0, 35, 210, 245mm. Square all marks across the tape with a fine pencil or biro.
9. Mark along each edge a nominal centreline. Mark it lightly, but not so light it's invisible later. Now set out the spacing between sides of your new seat frame. Again, mine was common at 445mm between centres. This saw me come equally in from the faintly marked centrelines, to about 13.5mm from the inside edge of each side of the riser. Now I had a set of crosshairs for all eight holes.
10. After double-checking the measurements, I centre punched each crosshair and pilot drilled to 3/32", then finished at 11/32". The riser was dry fitted to check holes and all good.
[Image: img20121230182907.jpg]
[Image: img20121230183004.jpg]
11. A light sand plus deburr, three coats of VHT satin black epoxy paint and the base looked like a bought one. Next step was to refit the seat belt buckle. I then inverted the new seat and bolted up the riser, torquing to firm but not stupid tight - the threads are not splendid!
[Image: img20121230183744.jpg]
[Image: img20121230194807.jpg]
12. Installation. To paraphrase Haynes, RITROR... Don't forget the underseat wiring!
You need basic mechanic's tools, plus an angle grinder with thin cutting disc and an electric or cordless drill with bits.
1. Remove the seat from the car - unplug the wiring first, then unscrew the four T-40 fasteners, taking note of the spacers under the seat (they vary in thickness by position). Unbolt the seat belt buckle stalk and slip it (with grommet) back into the seat riser.
2. With the seat in a safe place for grinding, release the seat base cover's edges from the metal riser base's side rails. Pull the cover back firmly to expose three stitch welds per side.
[Image: seatbaseweld2.jpg]
3. Grind carefully through the stitch welds, favouring a cut into the seat's tubular frame if there is a tight join. Complete one side, then flip the seat over to do the others. Set the old seat aside until the job is done - you may need to check its dimensions at some point.
[Image: seatbasetrimmed1.jpg]
4. Smooth the seat riser top edge with the grinder and disc, gently. Now lay a strip of inch masking tape along the length of each top edge.
5. Looking once again at the seat riser, note the 4mm wire "rails" that held the seat cover edges before. Where the wire rail turns up towards the riser top edge, at rear of the assembly, is your datum point. This turnup is clearly shown in the first photo. Mark the centreline of this wire turnup on your masking tape, both side - use a carpenter's square or similar if you have it.
6. On the original seat, the backrest pivot axle was 47mm past this datum. You may choose to set up your donor seat to preserve the same location. I decided to put the new seat 20mm further back, as its base was longer than the original and backrest slightly thicker.
7. This is the only slightly headbending part. First you measure from the backrest pivot axle (centreline) to the first mounting hole in the donor seat frame. For my seat, this was 60mm. You hold your ruler so the pivot distance (whether 47mm as original, or otherwise) reads on the datum line and the zero is at the pivot point. Now read from the zero, to that first bolt hole centreline and mark it on the tape. Do this both sides.
8. Now set out the other bolt holes, working each time from the first one set out on each side; don't "hop" from one to the next if there are more than two holes per side. In my case, I used all eight (four per side) as Citroën did on the Xantia donor. My spacings are quite common to various Pug/Cit cars and were (between centres) 0, 35, 210, 245mm. Square all marks across the tape with a fine pencil or biro.
9. Mark along each edge a nominal centreline. Mark it lightly, but not so light it's invisible later. Now set out the spacing between sides of your new seat frame. Again, mine was common at 445mm between centres. This saw me come equally in from the faintly marked centrelines, to about 13.5mm from the inside edge of each side of the riser. Now I had a set of crosshairs for all eight holes.
10. After double-checking the measurements, I centre punched each crosshair and pilot drilled to 3/32", then finished at 11/32". The riser was dry fitted to check holes and all good.
[Image: img20121230182907.jpg]
[Image: img20121230183004.jpg]
11. A light sand plus deburr, three coats of VHT satin black epoxy paint and the base looked like a bought one. Next step was to refit the seat belt buckle. I then inverted the new seat and bolted up the riser, torquing to firm but not stupid tight - the threads are not splendid!
[Image: img20121230183744.jpg]
[Image: img20121230194807.jpg]
12. Installation. To paraphrase Haynes, RITROR... Don't forget the underseat wiring!