Need help with wiper motor replacement

[Larry M.]

On a 64, mine was a service replacement. I bought a correct5044518 etc. form Corvette Specialties of MD West. I asked them to build it as a survivor, no replating. It looks good. I took my old one out today. Of course, everything you do is a learning process.

What I see is that there is a mounting plate riveted to the fiberglass firewall for the mounting of the wiper motor which is great. My old unit did NOT have the foam gasket for mounting against the firewall and plate (remember, somebody worked on this at some point in time). What it does have is a ring of black sealant (I think) which, due to having the wiper motor pressed against it, looks like a preformed gasket. So this is my first question: is there any other sealant behind the wiper motor other than the foam gasket??? Stated differently, should the mounting surface which is the firewall and metal plate with a large hole and four scree holes in it have any other material on it?

Second point, and I'm just looking for affirmation. I went into this thinking there was a metal spacer on the wiper motor arm under the dash. What I'm seeing is a plastic spacer between the right and left wiper push arms. Is this the only spacer?

[Edward J.]

Re: Need help with wiper motor replacement

Larry, The wiper motor has a round foam seal that fits around the snout of the motor no extra holes. If you head to Home Depot and get your self a do it yourself weatherstrip sealing kit for a door or window about 3/8 thick you should be fine with this. And the plastic spacer I believe is just a thrust washer of sorts to keep the arms from rubbing metal on metal.

[John H.]

Re: Need help with wiper motor replacement

Second point, and I'm just looking for affirmation. I went into this thinking there was a metal spacer on the wiper motor arm under the dash. What I'm seeing is a plastic spacer between the right and left wiper push arms. Is this the only spacer?

Larry -

The original spacer (which is frequently missing due to folks not knowing what it is or where it goes) was a thick fibrous/hard rubber washer that spaces the two wiper linkage arms apart on the motor drive lug so they don't hit each other; if the spacer is left off, the motor will produce a loud noise twice per revolution as the link arms interfere.


WiperSpacers.jpg

[Larry M.]

Re: Need help with wiper motor replacement

John, thank you. On closer inspection the one I have is rubber. It is mashed out so the ID is more than 3/4 inch. I'm guessing the original ID was around 9/16 to fit around the rolled crimp on the bushing for the arm first put on the stud. I'm thinking about using a nylon washer instead (sell then at Lowes). Do you see any issue with this plan.

[Joe R.]

Re: Need help with wiper motor replacement

Larry,

I'm no mechanical engineer, but I suspect the metal wiper arms will grind the nylon down to nothing. I got one from LICS recently, it's only $3.00. It's a lot of work to take apart and put back together to save less than three bucks. Just my humble opinion... Here's the part:

http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000370a~Z5Z5Z5AAAYS~P3.00~~~~S4010Q8F8M99523332180i~Z5Z5Z5~Z5Z5Z50000370a#

Joe

[Timothy B.]

Re: Need help with wiper motor replacement

I got one from Paragon or CC a few years ago and never liked the way it fit, the part seemed to just be rubber and in my thinking would never hold up.

The ID has to be large because there is no space between the brass bushings for it, is this part available from GM, or can some post the specs.

[Larry M.]

Re: Need help with wiper motor replacement

I think what I'm seeing is in sync with what Timothy says. What he calls "large ID" is the 9/16th I mention above to go around the rolled crimp on the rear bushing. It has to go around the bushing because there is no room in between. Therefore I suspect it is really just a noise control item. Of course if this is true then what John says is not right and he is seldom, if ever, wrong, so there may be more to this than I'm seeing. I'm going to go take another closer look to see if I could get the clip on with the arms spaced apart. Lowes sells rubber washers also and I bought a couple to look at ($0.98). They appear to have some fiber in them. The one I took out is still whole but deformed and is likely original or a GM part from the period. I'm going to look at that closely again.

[Larry M.]

Re: Need help with wiper motor replacement

I have it back together with no washer. I have zero clearance and had to use force to install the clip with no rubber spacer. I'm going to order the repro part and sometime I'll attempt to put it in but I think I'll need a compression clamp to get the job done. Watching the pattern of operation i don't see the opportunity for the link arms to interfere and I have no noise. Now, since I had an aftermarket motor the operating arm under the dash could be of different dimension than an original. The motor I bought did not come with one so I had to transfer the one I had (which is maked #4). Thanks for the comments on this post.