3800 Swap Getrag Refresh? (Page 1/1)
Stricken SEP 24, 02:30 PM
I'm about to drop the cradle from my 88 Formula today. I'm sticking with the Getrag and adding the Spec clutch, but I'm building up the 3800 to be in the 300whp region. Is there anything I should check over on the trans or anything that's easy/cheap to replace while it's out? I know the trans is iffy for this power level, but it's just going to be a DD with no trips to the drag strip any time soon. I have no idea what the history or miles of the trans are, but it looks very fresh. The case is clean, fluid is clear, doesn't leak a drop, and the CV boots are very new looking, so it appears to be in good shape externally.
Spoon SEP 24, 07:18 PM
Back in the day I had the opportunity to replace the spider gears (google it) in Dodge vans ans Jeeps. To get an idea how much wear was on the differential (transaxle in your situation) I'd jack up the rear and rotate one of the wheels to observe how much movement it took to get the opposite wheel to turn. Do some back & forth movements and the more slack the more wear that was expected.
For the ring and pinion gears a similar method was used. This slack is known as back-lash and is measured in degrees.

This should give you a rough idea how much slop or wear your trans has without cracking it open. If you want the real deal wait for others to chime in but this method only takes your eyeballs to check.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

hypo327 SEP 24, 09:34 PM
Whenever you pull your axles out of the transmission, always replace your seals, even if they look good, or if they are fairly new from other transmission work. They are cheap and you will avoid a possible oil leak. You can build yourself a good seal installation tool out of heavy duty PVC pipe, abot 4" long and a coupler fitting on each end. Using a convex file, you will have to gently file the inside diameter of the fitting to fit the seal perfectly... This will give you an even pressure on the seal to pound it in place with a rubber hammer. Works great! If they are old seals, it's best to replace them any way...!

About your clutch: If you buy a Spec, be sure to get the Spec 3+ ! The plus means its both street and track. I made a mistake once and ordered the Spec 3 (without the plus) which means it's track only. They are either on of off, no in between. They are the five puck design and just want to grab and go. Feathering them at all, like at a stop sign or light, will beat them to death. That's what happened to me, and the little spring came out and jammed against a flywheel bolt. Luckily that was all. It could have ruined my clutch and flywheel. As it was, I just had to replace the disc with a street/track version I got at a really good price on ebay, and all was well. I now run the Fiero Store heavy duty clutch by RAM, which has a larger disc and about equal torque strength as Spec 3+, and for about $100 less money. Fiero King that does allot of V-8 swaps, has been using them for years, and on his own 4.9 Formula and his 3.4 DOHC, and he drives them pretty hard. So, I tried one with my 3.4 swap for four years, and did a 3800sc swap using the same clutch on my Getrag, for going on another 3-years, with no problems at all. Plus you have an extra 1/2'' on the disc for a little more bite on the flywheel. Just an option for you...!

[This message has been edited by hypo327 (edited 09-24-2020).]

Stricken SEP 24, 09:56 PM
Um, well... There's this...