Early Chimaera steering rack pinion seal
Discussion
After two years of a weeping pinion oil seal, I finally got around to changing it this winter. My car is a 1995 Chimaera with the early power steering rack, the steel one not the newer aluminium one. The rack had been refurbished at some time in its life as it had a sticker with refitting cautions on the bottom of it.
I'd been putting off this job as I thought I'd have to remove the rack but after speaking to my friendly TVR garage I plucked up the courage to do it myself. It was quite straightforward but fiddly and messy as you can imagine.
Firstly, I marked the original positions of the steering column joints with a white marker pen. I sprayed the universal joint splines with lots of penetrating fluid and removed the bolts and nuts. I ended up not messing around with the joint closest to the wheelarch as the splines didn't budge with moderate force and I felt that I would gain more space to remove the lower universal by removing the 4x M8 bolts that hold the rack to the chassis.
So that's what I did next, separated the main rack from the chassis just those 4x bolts and then the lower universal slid off the pinion splines and lower splined rod (not sure what the proper name is).
After cleaning up around that area the circlip and thin spacer washer were removed. Yes it was tricky removing the circlip but it can be done using some cheap Machinemart pliers.
Before I passed the point of no return and removed the pinion seal I noted the dimensions of the original which were:
20x30x7/8
Corteco 12016820B
This turns out to not be a straightforward seal but a double lip step seal that is more commonly found on truck racks. I tried phoning around the usual suppliers, garages and seal suppliers but surprisingly I wasn't confident they had the right seal for me. The 20x30x7 is common but the step seal isn't. In the end I found Preston Power Steering knew what I was after and they were very helpful with advice (thanks Dave!) on how to swap it out too. Total price for the seal was £12.50 delivered.
Once I had the seal I cleaned the pinion area very carefully with turps and paper towels so that it was as clean as can be. I prised out the old one using the self tapper method and a small trim tool as a lever. Any remaining fluid in the system came out but I was resigned to a bit of mess. It didn't take much oomph to get it out. The original seal was very hard as compared to the new one. Pressing the new one was quite straightforward too. A whisper of grease on the outer and inner surfaces and it pressed easily over the pinion by hand. The final seating of the seal was done using a 22mm deep socket (actually an oxygen sensor socket). Again just pressing by hand did the trick. No struggling required.
Next the spacer and circlip went back in plus a dustcap to cover the seal area as my car didn't have one. I made it from a shampoo cap and the dimensions were 14mm for the pinion diameter and a diameter of >43mm to clear the casing. The only tricky bit of rebuilding the rack components up was getting the centre position of the rack lined up with the centre position of the steering wheel. This just took some trial and error maneuvering the spline position on the lower universal but near enough will do for now.
The final item of note was that I fitted a filter on the return line. MAPCO 29991. When I rinsed out my reservoir I used turps and when I poured the waste out into a clear jam jar it sparkled in the daylight! Thought the filter might help the system last a bit longer. Bleeding was done using the usual method of starting the car on axle stands and slowing turning the steering wheel slowly from side to side. The system made lots of noise clearing the air but it quietened down soon enough.
All in all a job worth doing and a cheap fix. Hope this useful for people with the early steel steering racks.
I'd been putting off this job as I thought I'd have to remove the rack but after speaking to my friendly TVR garage I plucked up the courage to do it myself. It was quite straightforward but fiddly and messy as you can imagine.
Firstly, I marked the original positions of the steering column joints with a white marker pen. I sprayed the universal joint splines with lots of penetrating fluid and removed the bolts and nuts. I ended up not messing around with the joint closest to the wheelarch as the splines didn't budge with moderate force and I felt that I would gain more space to remove the lower universal by removing the 4x M8 bolts that hold the rack to the chassis.
So that's what I did next, separated the main rack from the chassis just those 4x bolts and then the lower universal slid off the pinion splines and lower splined rod (not sure what the proper name is).
After cleaning up around that area the circlip and thin spacer washer were removed. Yes it was tricky removing the circlip but it can be done using some cheap Machinemart pliers.
Before I passed the point of no return and removed the pinion seal I noted the dimensions of the original which were:
20x30x7/8
Corteco 12016820B
This turns out to not be a straightforward seal but a double lip step seal that is more commonly found on truck racks. I tried phoning around the usual suppliers, garages and seal suppliers but surprisingly I wasn't confident they had the right seal for me. The 20x30x7 is common but the step seal isn't. In the end I found Preston Power Steering knew what I was after and they were very helpful with advice (thanks Dave!) on how to swap it out too. Total price for the seal was £12.50 delivered.
Once I had the seal I cleaned the pinion area very carefully with turps and paper towels so that it was as clean as can be. I prised out the old one using the self tapper method and a small trim tool as a lever. Any remaining fluid in the system came out but I was resigned to a bit of mess. It didn't take much oomph to get it out. The original seal was very hard as compared to the new one. Pressing the new one was quite straightforward too. A whisper of grease on the outer and inner surfaces and it pressed easily over the pinion by hand. The final seating of the seal was done using a 22mm deep socket (actually an oxygen sensor socket). Again just pressing by hand did the trick. No struggling required.
Next the spacer and circlip went back in plus a dustcap to cover the seal area as my car didn't have one. I made it from a shampoo cap and the dimensions were 14mm for the pinion diameter and a diameter of >43mm to clear the casing. The only tricky bit of rebuilding the rack components up was getting the centre position of the rack lined up with the centre position of the steering wheel. This just took some trial and error maneuvering the spline position on the lower universal but near enough will do for now.
The final item of note was that I fitted a filter on the return line. MAPCO 29991. When I rinsed out my reservoir I used turps and when I poured the waste out into a clear jam jar it sparkled in the daylight! Thought the filter might help the system last a bit longer. Bleeding was done using the usual method of starting the car on axle stands and slowing turning the steering wheel slowly from side to side. The system made lots of noise clearing the air but it quietened down soon enough.
All in all a job worth doing and a cheap fix. Hope this useful for people with the early steel steering racks.
thats the same top seal dimensions as the all alloy rack fitted to these cars too 
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