Rear Diff Companion Flange Swap 4cyl-V6?

[hobiesbestfriend]

Got myself a good deal on a V6 3rd for my 85 Runner. I also have an 86(I think) IFS Rear axle that I'm going to put in. Same gears just wanted to bolt it in, but it appears the bolt pattern is wider on the V6 companion flange. Is it possible to just unbolt the two stakenuts and swap flanges without everything coming out of adjustment? If not, what's my best option? Should I swap in the V6 driveshaft and T-Case output flange? Is the driveshaft any bigger/tougher thus making a point to spending more money on a driveshaft?

 

[jasonmt]

Rotate the driveshaft 45 degrees on the flange, punch new marks with a transfer punch and drill new holes.

 

[2ndGenToyotaFan]

Are you sure you aren't 90 degrees out? The bolt pattern is not a square.... I'm pretty sure the nut that holds the flange on also holds all the other guts, so taking it off and swapping the 4 banger flange would not be a quick fix. If it's not 90 out, just redrill as suggested.

 

[hobiesbestfriend]

Rotate the driveshaft 45 degrees on the flange, punch new marks with a transfer punch and drill new holes.

probably gonna go this route as it sounds the easiest. 10mm holes, any tips on the best way to make sure they are at 90 degrees?

Are you sure you aren't 90 degrees out? The bolt pattern is not a square.... I'm pretty sure the nut that holds the flange on also holds all the other guts, so taking it off and swapping the 4 banger flange would not be a quick fix. If it's not 90 out, just redrill as suggested.

I'll check again on the two 4cyl diffs I have. Almost positive they were square pattern at 60mm centres. The v6 is about 66mm centres.

Of course there is always the room for "I'm an idiot" error, so will measure everything up tomorrow morn and make sure I'm not making up problems to solve.

 

[2ndGenToyotaFan]

I could be wrong, but I seem to remember always having to turn stuff to get the shaft back on right......

 

[87toycrawler]

bolt pattern is different ! you can switch the flanges with out any real effect on the internals just take an impact and and run the new nut down till it first stops turning making sure the crush sleeve doesn't crush any more. use loctite .

 

[WarDamnEagle]

I thought the V6 third would drop right into a 4 cyclinder axle and bolt up. I have been looking at installing a TRD elocker third in my 85 4Runner rear and I was led to believe that the driveshaft flange would bolt right up. (I know all about the axle modifications that have to be made.) Sounds like this might not be the case??

Just curious why you're thinking about going to the V6 rear axle? It's a couple of inches wider than your 85 axle. Is it for the larger brakes? Are you going to run spacers up front? Just curious.

 

[the truck doctor]

I installed a trd e-locker from a 2001 v6 prerunner in my 89 4banger axle and after the mods to the axle housing the drive shaft bolted right up. I'll post pics later tonight!

 

[elvi]

I thought the V6 third would drop right into a 4 cyclinder axle and bolt up.

Odd; I pulled 3 V6 rears; a 88, and 91 and a 93. All have the same flange and bolted up to my 93 with a W56 \ 22RE. (Swapped from the stock 4.10 to a V6 4.56) Any detail on what years they changed? 95+?

 

[hobiesbestfriend]

Just curious why you're thinking about going to the V6 rear axle? It's a couple of inches wider than your 85 axle. Is it for the larger brakes? Are you going to run spacers up front? Just curious.

I was just gonna rebuild my current(85) axle and source the larger brake assemblies and swap them on. I found a rear axle from an 86 4 cyl that had low mileage for a $100 and it came with the leafs which I needed anyway for the custom front leafpack I'm making. I haven't actually measured yet, but I will today when I pull the old axle, but I think the axle tubes look bigger in the 86 axle? Anyone know anything about that? They seem sort of stepped. And yes, it's 3 inches wider. I figure this can't hurt as It's a 4runner and it will have a custom roofrack/rooftop tent and be used for DD/Expedition/mild off-road use. As such, a slightly wider track can't hurt for stability. Not gonna use spacers up front.

I got the V6 centre section from an 89 V6 4 Runner with R150, (151?) can't recall for sure. I was planning on swapping in a Toyota LSD from an older Supra, but might not go that way after all. If I was though, I'd need the V6 3rd. The housing is a bit beefier, and I like the idea of the 4 pinion/4 spiders.

I used an old companion flange from my front axle(same bolt pattern as rear on 85 anyway), turned 45 degrees, to mark my new V6 Companion flange holes.

Question: Do I need a gasket for the rear axle backing plates and 3rd member? Can I just use gasket maker or the like?

 

[WarDamnEagle]

Question: Do I need a gasket for the rear axle backing plates and 3rd member? Can I just use gasket maker or the like?

I can't say from personal experience but after much research on this website on the same question, I have concluded that the Toyota Red (RTV?) is the way to go. I have read several threads in this section and in the 80 section where they have had diff leaks with the gasket and several went back with just the RTV. One seemingly knowledgable person said they put a layer on both faces, waited 15 minutes and then bolted it together.

The only disadvantage apparently, from what I've read, is that it's a bitch to get the diff back off later!

 

[WarDamnEagle]

Here is the best thread that I've read regarding the question of gasket use on differentials:

https://forum.ih8mud.com/80-series-tech/161098-use-toyota-red-gasket-stuff-when-replacing-diffs.html

 

[hobiesbestfriend]

Kinda what I figured as well, gonna go with the FIPG I usually use. I have black and so far have only used it for engine assembly. There is red, but whether it really makes a difference. I think the most important thing is to make sure the prep is done properly. I'll keep you posted