crazyhorse1056 109 #1 Posted August 29, 2015 i have a diff gear stamp 7242 would like to know what transmission it will work with Share this post Link to post Share on other sites
Racinbob 11,263 #2 Posted August 29, 2015 Can you post a picture? I'm not seeing that # on any list. Share this post Link to post Share on other sites
Racinbob 11,263 #4 Posted August 29, 2015 Are you sure the last 2 isn't a 3? It looks like the differential case and gear out of a 5003/5010. Originally a 3502 replaced by part #7243. Hopefully Mike and/or Steve will chime in. Share this post Link to post Share on other sites
crazyhorse1056 109 #5 Posted August 29, 2015 no it's 7242 i was thinking it was the same as the 7243 Share this post Link to post Share on other sites
Racinbob 11,263 #6 Posted August 29, 2015 Well, ya got me befuzzled. Let's wait for the gurus. Steve probably won't be back until the first of the week. I think he's goofing off in Minnesota. By the way, are we talking about either a 5003 or 5010 transmission? Share this post Link to post Share on other sites
crazyhorse1056 109 #7 Posted August 29, 2015 yes I'm redoing a 5003 Share this post Link to post Share on other sites
Racinbob 11,263 #8 Posted August 30, 2015 (edited) Reading your first post again you're wanting to know what it fits in. The part looks new. No worries, I'm sure you'll get an answer here. My brain shifted into the wrong gear Edited August 30, 2015 by Racinbob Share this post Link to post Share on other sites
stevasaurus 22,893 #9 Posted August 31, 2015 That is the newer style differential with the bolt on bull gear. It will fit in either the 5003 (RJ's) or the 5010 (Suburbans) transmissions. It requires the correct mushroom gear to match the teeth with the bull gear. You need part #3559...this part should be in all the 5010's, The RJ's came with #3502 which has 8 teeth on the upper part of the mushroom gear...the #3559 (I believe) has 11 teeth. Give us a picture of your mushroom gear if you would. 1 Share this post Link to post Share on other sites
crazyhorse1056 109 #10 Posted September 1, 2015 This one has 11 teeth and my old one has 8 teeth do you know what side cover to use with the 11 teeth gear needle bearing or ball Bearing Share this post Link to post Share on other sites
stevasaurus 22,893 #11 Posted September 1, 2015 That is the correct mushroom (11/44 toothed) gear for that bull gear on the differential housing. If you look at your old mushroom gear it and your old differential housing with bull gear have less teeth. You can just switch them both out with no problem. As far as the 2 side plates, you can use either one of them also since both bearings have the 3/4" ID. The needle bearing side plate is the improved version. The S8K ball bearing is designed to have some wiggle room for the mushroom gear with brake drum shaft...it was wearing out those bearings faster then if they had the needle bearing in there. Therefore, the needle bearing is the better choice...BUT...you are doing a #5003 transmission. The needle bearing plate should have the bake band mount at 45 degrees, you are going to want a plate with the brake band mount at vertical...unless you want to make a few linkage changes so the brake works. Hope that kind of explains things. Here is a short video of your differential...https://www.youtube.com/watch?v=1SAJ3lU3gIg Share this post Link to post Share on other sites
crazyhorse1056 109 #12 Posted September 1, 2015 Yes it does and I have both types of side plates for the 400 transmission thanks for the help Share this post Link to post Share on other sites
