Defective Aftermarket Replacement Parts

I keep reading about how many of you have received defective aftermarket replacement parts, from body panels to suspension items to seals to windshields.

I’m fortunate to have restored my car back when many NOS parts were still available (1985 - 1987), and even the aftermarket items were of good quality. Thus, this subject intrigues me.

Would anyone care to chime in about what you received, how it was wrong, and what you did about it?

Mine was the replacement rocker panel I got for Tweety, bought in 2004. It was shite: I had to reshape it and add material to it to get it to fit the rocker.

Then, there are the bad quality Rolon chain tensioners, which fortunately, I found out about just before I installed one in the Jaguar, and two in my Rover. I spent a lot of money finding the original Renolds tensioners, which was money well-spent.


Before eveyone piles on with their defective parts stories, I would like to say that I have purchased tens of thousands of dollars of parts, mainly from SNG Barratt. I would estimate my rate of defective parts as less than 1%. And SNG has made those few situations good without any squacks or pushback.

Unfortunately, in the world of auto parts, we are small fish in a small pond. For some parts, there may only be one fabricator of them. If they are having a bad day or worse a bad month, or just don’t give a damn, the damage is done. We are the Beta testers. I think SNG is pretty good at weeding out the ones that don’t give a damn. I like to establish a relationship with a supplier and stick with them. I don’t chase lowest price. Sometimes you really do get what you pay for.

As Wiggles points out, the Rolon chain tensioners are known junk. I’m sure others will bring up other examples. Regarding sheet metal, the cars were hand built. Under the circumstances, I always expect to fettle on my sheet metal. Just part of the journey.

We have a policy of not trashing vendors but good words are not prohibited, are they. I would give a positive shout out to SNG, EtypeFabs, Monocouque-Metalworks, Rhode Island Wiring, and Coolcat for stuff that has fit well, minimal hassles.


In 2015 I bought a pair of fuel pressure regulators from a popular supplier, and installed them along with a gauge. I was stunned when I pressurized the v12 and watched the gauge drop to zero in around 30 secs.
I made up a test rig, and , along with a pressurized air tank, drove for two hours to the supplier, where I demonstrated the poor quality of the FPR’s. I got my money back. Reluctantly.

I concur: that said, Ive only done bidness with CoolCat and SNG, and I have nothing but good to report on both.

I may be a little bit less charitable than you, Harvey: I know Jags were essentially hand built, and I give them a lot of leeway on that when it comes to replacement tin parts.

That said, the rocker panel I got was so far off base as to be laughable. I can’t tell you where it came from, or what manufacture it was, because I bought it from a parts guy here in town and I don’t know where he got it from. I suspect it was Martin Robey.

Well, there is fettlling and then there is “WTF”. I haven’t done enough sheet metal to establish a ratio between the two!

Why Robey’s parts? Robey produced complete E-Type bodyshells. Actually, Robey was one of the earliest suppliers of aftermarket as well as genuine OEM parts. I purchased a lot of parts from them for the total restoration of my '62 Coupe, albeit some time ago but I was quite happy with their service.

Not so much back then for some of the others often touted here

1 Like

As I said, Clive, not sure if it came from Martin or not, back then there were fewer people that were supplying those kind of things. Just an assumption on my part.

Great experience with Cool cat,bought a fan 10 years ago,hadn’t arrived after a considerable amount of time,no problems they sent me another,eventually both arrived and they told me to keep them both.
Bought a few springs for a gearbox rebuild a few months ago,one was coil bound and the other bore no resemblance to what it was replacing in terms of wire gauge or length…threw them both over the fence.
In the process of buying a complete set of frames from EType fabs,Uryk couldn’t be more helpful, including offering to pack an interior kit from a totally unrelated supplier in with my frames to save me shipping costs.
Last but not least,Rob Beere,again packed parts from unrelated suppliers (excellent indicator lenses from Marek) in with my order,superb fit and finish of the parts I bought from him.

Robey rocker panels don’t go within a bull’s roar of fitting. They may have fixed it by now, but as of a couple of years ago, their S3 engine frames were just wrong. It took a long email exchange to convince Martin that their geometry was wrong. Then straight after that we received S2 engine frames where the lower tube where it connects to the plate that the picture frame bolts to, interfered with the head of a bolt.

Then there was the boot floor/lower quarter panel for an S3. Metal had to be added to get the area where the LH taillight fits, to comply with the shape of the taillight. Metal also had to be added to get the lower quarter panel area of the panel to fit correctly with the upper quarter panels of the car. The car was a totally unmolested vehicle, with the panel being replaced due to rust only.

Their floors for LWB cars are seldom correct. It would seem that the strengthening features are pressed then the side of the floor where it comes up to interface with the sill is then folded; that part is wrong most of the time.

In their defense, they made good an exchange or refund quickly. Not so with Jaguar Classic.

A lower valance panel from Jaguar Classic was so poorly made and out of shape, that we ended up chopping it up and using parts of it to repair the original panel. They only give a two week warranty from the date of purchase; perhaps that’s an indication of the confidence they have in the parts they make.



Seems to have been a batch of defective pressure plates (spring in my case) that have cost several of us the price of an engine out redu

1 Like

Hi Harvey,
Many parts are stamped and or machined parts and they’re wrong. I just received three of the same part that is a stamped part, so no bad day, bad month affect possible, where critical hole features are way too small. It’s not just a simple fix of running a correct drill size through the holes, as the holes break into each other. Particularly with a mechanical part reproduction, they don’t have to design the part, just copy whats already there.


You will find that Uryk’s frames are nothing short of magnificent. Bought mine five years ago. Paul.

Hi, my favorite aftermarket story was getting the trunk to latch and match the body of my 65 OTS. Spent years collecting NOS parts, like a NOS temperature sensor which is Cad plated with a black insulator. You won’t see many cars with the correct temp sensor. Spent 14 hours trying to get the friggen latch to catch where the lid was even with the body. Well a few days later there on was a NOS latch which wasn’t cheap, but it took a little over 15 minutes to fit perfectly. Most aftermarket today is off by an 1/8 th of an inch, or made cheaply. Recently got door handles from SNG for my 420. Mounting holes on the inside were both 10-32 threads AND 6 mm. Who does this? probably Chinese.

Anybody else go back far enough that they had to make their own rocker panels… because the car was too new to need replacement parts imported, and old enough that the rockers dissolved. ('64 in '74) They were $500.00 cars, nobody had many parts for them, they were being tossed.

I made the rockers in metal shop and installed them in the auto shop.

Now, you just click a finger. Pfffft. :crazy_face:

The cool thing was, I had the only restored Series I at car shows. All the others were perforated and a ratty mess.

1 Like

Should we now exit your lawn?


1 Like

In the past year (the extent of my E-type parts experience) -

  1. Incorrect thread on the wing nuts for the air filter box. The delivered parts had metric threads!! This was never really resolved - it occurred right when Covid hit and I was supposed to get back in touch with them once things got back to normal, and I’d forgotten about it until just now. Guess I need to give them a call.
    Dual stromberg delta airbox wing nuts

  2. Two reservac check valves that wouldn’t hold vacuum in a bench test. Resolved with the vendor, but they weren’t concerned that their supply of valves had an issue. I ordered the third one from a different supplier (SNG) and it worked great.
    Brake Servo Vacuum Tank Check Valve - #23 by ryaskovic

  3. A tie rod end that didn’t articulate enough (110° vs ~125°). Resolved with the vendor. It was really an anomaly having to do with old parts numbers, that the vendor has addressed so it shouldn’t happen again, for me or others.
    RobY / '68 S1.5 OTS resurrection - Part 1 - #161 by ryaskovic



Another item that is frequently reported as being defective is the one-piece front lower ball joints. Bolt holes don’t line up with those in the upright - not even close. The Lemforder version is the commonly listed version that DOES fit. What baffles me with items like this is that the defective part really can’t be modified to work, so surely customers must return them. So, how does the supplier not get to find out that they are shipping trash?

This is one of the parts I received - the lens for the rear license plate lamp on a 1963 OTS:

The two examples are from different vendors. The finger is holding the rear of the left example flat on the surface. The Salvador Dali version was 1/4" away from being flat! I guess the glass was removed from the mould before it was solid. I can imagine such a thing happening, but how does it get all the way to an end customer without someone noticing?


Day 1 of Taxi Driver School: ‘He was already dead when I hit him’.

Day 1 of Parts Supplier School: ‘You are the first customer to have this problem’.

1 Like

Day 2: " No one else has ever reported a problem."